globalbehaviorofsolutionsinapredator-preycross-diffusion...
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Research ArticleGlobal Behavior of Solutions in a Predator-Prey Cross-DiffusionModel with Cannibalism
Meijun Chen Shengmao Fu and Xiaoli Yang
College of Mathematics and Statistics Northwest Normal University Lanzhou 730070 China
Correspondence should be addressed to Shengmao Fu fusmnwnueducn
Received 20 February 2020 Accepted 7 May 2020 Published 22 May 2020
Academic Editor Lucia Valentina Gambuzza
Copyright copy 2020 Meijun Chen et al is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
e global asymptotic behavior of solutions in a cross-diffusive predator-prey model with cannibalism is studied in this paperFirstly the local stability of nonnegative equilibria for the weakly coupled reaction-diffusion model and strongly coupled cross-diffusion model is discussed It is shown that the equilibria have the same stability properties for the corresponding ODE modeland semilinear reaction-diffusion model but under suitable conditions on reaction coefficients cross-diffusion-driven Turinginstability occurs Secondly the uniform boundedness and the global existence of solutions for the model with SKT-type cross-diffusion are investigated when the space dimension is one Finally the global stability of the positive equilibrium is established byconstructing a Lyapunov function e result indicates that under certain conditions on reaction coefficients the model has nononconstant positive steady state if the diffusion matrix is positive definite and the self-diffusion coefficients are large enough
1 Introduction
In 1999 Magnusson [1] proposed the following predator-prey model
dX
dt minus MmatX + AY + BXY + CXZ
dY
dt RX minus AY minus MjuvY minus SXY
dZ
dt TZ minus UZ
2minus VXZ
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(1)
where X Y and Z represent the biomasses of adult pred-ators juvenile predators and prey respectively Mmat andMjuv represent the death rates of adult predators and juv-enile predators respectively A denotes the specific rate ofjuveniles recruited to the adults class R denotes the birthrate T and U are logistic coefficients S represents thecannibalism attack rate B cS where c is the conversionefficiency of eaten juveniles into adult biomass and thebiological meanings of V and C are similar to S and B Formore details on model (1) please refer to [1]
Let
u S
MmatX
v SA
M2mat
Y
w C
MmatZ
1113957t Mmatt
(2)
and still denote 1113957t by t then (1) becomes
du
dt minus u + v + auv + uw
dv
dt bu minus gv minus uv
dw
dt sw minus rw
2minus euw
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(3)
HindawiComplexityVolume 2020 Article ID 1265798 19 pageshttpsdoiorg10115520201265798
where
a BMmat
SA
cMmat
A
b RA
M2mat
g A + Mjuv
Mmat
s T
Mmat
r U
C
e V
S
(4)
We can see that e is the only parameter depending on S
in system (3)Most works on cannibalism adopt a McKendrickndashvon
Foerster age-structured model [2ndash4] but the model isusually rewritten as an ODE system or nonlinear Volterraintegral equations [4 5] In 1995 Kohlmeier and Ebenhoh[6] studied a two-dimensional ODE model without anystructure and they obtained that in some cases cannibalismcan lead to a higher long term predator stock size en vanden Bosch and Gabriel [7] found that cannibalism canstabilize a predator-prey system in a structured model wherethe oscillations are due to age structure
Magnusson [1] discussed model (1) which is in someways a simplification of the system studied by van den Boschand Gabriel in [7] Magnusson made two simplificationsFirstly it is assumed that all juveniles are vulnerable topredation by the adults Secondly instantaneous maturationinto the adult class is proportional to the present juvenilebiomass ie a constant per capita rate of maturation and
making this simplifying assumption means that any oscil-lations that may occur are not caused by a delay inherent inthe system Moreover the stability and Hopf bifurcation ofsolutions for system (3) were studied in [1] e authorobtained the following conclusions On one hand if themortality rate of juveniles is low andor the recruitment rateto the mature population is high then there is a stableequilibrium with all three population sizes as positive Onthe other hand if the mortality rate of juveniles is high andor the recruitment rate to the mature population is low thenthe equilibrium will be stable for low levels of cannibalismbut a loss of stability by a Hopf bifurcation will take place asthe level of cannibalism increases
As we all know the growth of biological populationdepends not only on time but also on spatial distributionSpatial species interaction includes the self-diffusion whichis the natural dispersive force of movement of individualand the cross-diffusion that is the population fluxes of onespecies due to the presence of other species [8ndash16] ere-fore taking into account the effect of competition for re-sources on species growth law we are naturally led to thefollowing weakly coupled reaction-diffusion model
ut d1Δu minus u + v + auv + uw x isin Ω tgt 0
vt d2Δv + bu minus gv minus uv x isin Ω tgt 0
wt d3Δw + sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(5)
and the Shigesada-Kawasaki-Teramoto model with stronglycoupled cross-diffusion
ut Δ d1u + α11u2 + α12uv + α13uw( 1113857 minus u + v + auv + uw x isin Ω tgt 0
vt Δ d2v + α21uv + α22v2 + α23vw( 1113857 + bu minus gv minus uv x isin Ω tgt 0
wt Δ d3w + α31uw + α32vw + α33w2( 1113857 + sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(6)
where Ω sub Rn is a bounded domain with smooth boundaryzΩ and η is the outward unit normal vector of the boundaryzΩ zη zzη e coefficients di(i 1 2 3) are the diffu-sion rates of u v andw αii(i 1 2 3) are referred as self-diffusion pressures and αij(ine j i j 1 2 3) are cross-diffusion coefficients which may be positive negative or
zero [17] e functions u0 v0 andw0 are nonnegativefunctions which are not identically zero
Very recently Zhang et al [18] found that the positiveequilibrium of (3) with r 0 can undergo stability switch(from stable to unstable to stable or from unstable to stableto unstable) with the change of the cannibalization rate
2 Complexity
eir results indicate that large cannibalization rate canmake the positive equilibrium globally stable although itsstability would change with the increase of the rate In factan important research subject for cannibalism models is thestabilizingdestabilizing effect of cannibalism [1 6 19] Forthis we need to compare the effect of cannibalism on thedynamic behavior for the ODE system the semilinear re-action-diffusion system and the quasi-linear cross-diffusionsystem
In this paper we first prove that stability properties ofequilibria for the ODE model (3) and the semilinear reac-tion-diffusion model (5) is similar but under suitableconditions on reaction coefficients cross-diffusion-drivenTuring instability in the quasi-linear model (6) occurs It isfound that the cross diffusion rate α13 is a decisive factor ofdestabilizing positive steady state that is cannibalism has nolonger a stabilizing effect en the uniform boundednessand the global existence of time-varying solutions for thecross-diffusion system (6) are investigated by using theenergy estimates and GagliardondashNirenberg-type inequalitieswhen the space dimension is one Finally some criteria onthe global asymptotic stability of the positive equilibriumpoint for (6) are given by Lyapunov function e obtainedresults indicate that for any cannibalism rate e undercertain conditions on the other reaction coefficients themodel has no nonconstant positive steady state if the dif-fusion matrix is positive definite and the self-diffusion co-efficients are large enough
Moreover we in [14] discussed another cross-diffusionmodel
ut minus d1Δu minus u + v + auv + uw x isin Ω tgt 0
vt minus Δ d2v +d4v
ε + u21113888 1113889 bu minus gv minus uv x isin Ω tgt 0
wt minus d3Δw sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(7)
where d4 is a cross-diffusion coefficient and ε is a positiveconstant (please refer to [12]) We proved that ifa b g s r e ε d1 d2 and d3 are fixed such that0lt εlt ε0 aglt 1 rgt s and (9) (see Section 2) hold then thereexists a positive constant dlowast4 such that (7) has at least onenonconstant positive steady state for d4 gedlowast4 is impliesthat the cross-diffusion rate is the decisive factor of
destabilization on the constant positive steady state andtherefore cannibalism is an auxiliary destabilizing forceRecently in another paper we detailedly describe the localstructure of the nonconstant steady states and discuss thestability and instability of the steady state bifurcation
2 Linearization Analysis
In this section according to the linearization analysis andRouthndashHurwitz criterion we focus on discussing the sta-bility of the reaction-diffusion system (5) and cross-diffusionsystem (6) To this end we first introduce the stability of theODE system (3)
21 ODE Model (3) Obviously problem (3) has trivialequilibrium E0(0 0 0) semitrivial equilibrium E1(0 0 sr)and E2((g minus b)(ab minus 1) (g minus b)(ag minus 1) 0) if glt blt 1aor ggt bgt 1a Moreover if r 0 bltg + ((s(1 minus ag))(e + as)) then a positive equilibrium point is given byE3(u v w) where
u s
e
v bs
eg + s
w e(g minus b) + s(1 minus ab)
eg + s
(8)
If rne 0 andbr + gs minus grgt 0
s + eg + r(1 minus ab)gt 0
s(1 minus ab) + e(g minus b)gt 0
⎧⎪⎪⎨
⎪⎪⎩(9)
then a positive equilibrium point is uniquely given by1113957u (1113957u 1113957v 1113957w) where
1113957u α +
α2 + 4eβ
1113968
2e
1113957v b1113957u
g + 1113957u
1113957w s minus e1113957u
r
α abr + s minus r minus eg
β br + gs minus gr
(10)
In fact the stability of these nonnegative equilibria in (3)has been obtained in [1] as follows
(1) E0 is unconditionally unstable(2) E1 is locally asymptotically stable if slt r and is
unstable if sgt r(3) E2 is locally asymptotically stable if glt blt 1a and is
unstable if bltg + ((s(1 minus ag))(e + as))
Complexity 3
(4)
(a) If aglt 1 then E3 is locally asymptotically stable(b) If aggt 1 S 0 (ie e⟶infin) and bltg then E3
is locally asymptotically stable(c) If aggt 1 Sne 0 (ie eneinfin) bltg and ablt 1 then
there exists elowast such that E3 is locally asymp-totically stable when egt elowast and is unstable whenelt elowast
Now we give the stability of 1113957u with respect to model (3)
Theorem 1 -e positive equilibrium 1113957u of (3) is locally as-ymptotically stable if aglt 1
Proof e Jacobian matrix of (3) to the generic us (us
vs ws) reads
J us( 1113857
j11 j12 j13
j21 j22 j23
j31 j32 j33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (11)
wherej11 minus 1 + avs + ws
j12 1 + aus
j13 us
j21 b minus vs
j22 minus g minus us
j23 0
j31 minus ews
j32 0
j33 s minus 2rws minus eus
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(12)
A direct calculation yields that the characteristic equa-tion of J(1113957u) is
φ(λ) |λI minus J| λ3 + α1λ2
+ α2λ + α3 0 (13)
with
α1 11113957u
g1113957u + 1113957v + +1113957u2
+ r1113957u1113957w1113872 1113873gt 0
α2 11113957u
(1 minus ag)1113957u1113957v + r1113957w(1113957v + g1113957u) +(e + r)1113957u2
1113957w1113872 1113873
α3 11113957u
e1113957w1113957u2(g + 1113957u) + r(1 minus ag)1113957u1113957v1113957w1113872 1113873
α1α2 minus α3 r1113957w1113957u2
+ (1 minus ag)1113957v + 2gr1113957w + re1113957w2
+ r2
1113957w2
1113872 11138731113957u
+ rg2
1113957w + e1113957v1113957w + 2r1113957v1113957w + gr2
1113957w2
+(1 minus ag)g1113957v +r1113957w1113957v2
1113957u2 +11113957u
middot (1 minus ag)1113957v2
+ r2
1113957w21113957v + 2gr1113957v1113957w1113872 1113873
(14)
It is easy to see that α3 gt 0 and α1α2 minus α3 gt 0 thanks toaglt 1erefore by RouthndashHurwitz criterion we know that(1113957u 1113957v 1113957w) is locally asymptotically stable
Notice that the unstable equilibrium points of (3) arealso unstable for (5) and (6) erefore for systems (5) and(6) we only discuss the stability of the equilibrium pointswhich are stable for (3)
22 Weakly Coupled Reaction-Diffusion System (5) Let 0
μ1 lt μ2 lt μ3 lt middot middot middot be the eigenvalues of the operator minus Δ on Ωwith the homogeneous Neumann boundary condition andlet E(μi) be the eigenspace corresponding to μi in H1(Ω)Let X be the closure of [C1(Ω)]3 in [H1(Ω)]3ϕij j 1 2 dimE(μi)1113966 1113967 be an orthonormal basis of
E(μi) and let Xij cϕij c isin R31113966 1113967 en
X oplus+infin
i1Xi
Xi oplusdimE μi( )
j1Xij
(15)
For system (5) by the linearization analysis and somesimilar arguments to the proof of eorem 2 andeorem 3in [12] we can obtain the following two theorems
Theorem 2
(1) -e semitrivial equilibrium E1 of (5) is locally as-ymptotically stable if slt r
(2) -e semitrivial equilibrium E2 of (5) is locally as-ymptotically stable if glt blt 1a
(3) -e positive equilibrium E3 of (5) is locally asymp-totically stable either aglt 1 or aggt 1 S 0 (iee⟶infin) and bltg
Proof We only prove (3) e proof of (1) and (2) is similarto (3) so we omit it here Let u (u v w)D
diag(d1 d2 d3) and L DΔ + J(E3) where j11 minus (be(eg + s))lt 0 j12 (e + as)egt 0 j13 ugt 0 j21 (beg(eg + s))gt 0 j22 minus (g + u)lt 0 j23 0 j31 minus ewlt 0
and j32 j33 0 e linearization of (5) at E3 is ut LuFor each ige 1 Xi is invariant under the operatorL and λ isan eigenvalue of L if and only if it is an eigenvalue of thematrix minus μiD + J(E3) for some ige 1 in which case there is an
eigenvector in Xi Denote the characteristic polynomial ofminus μiD + J(E3) by φi(λ) λ3 + Aiλ
2 + Biλ + Ci whereAi μi d1 + d2 + d3( 1113857 minus j11 + j22( 1113857
Bi μ2i d1d2 + d2d3 + d1d3( 1113857 minus μi d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ j11j22 minus j12j21 minus j13j31
Ci μ3i d1d2d3 minus μ2i d1d3a22 + d2d3j11( 1113857
+ μi d3j11j22 minus d3j12j21 minus d2j13j31( 1113857 + j22j13j31
(16)
A straightforward computation gives Hi AiBi minus Ci
I1μ3i + I2μ2i + I3μi + I4 where
4 Complexity
I1 d21 d2 + d3( 1113857 + d
22 d1 + d3( 1113857 + d
23 d1 + d2( 1113857 + 2d1d2d3
I2 minus j11 d22 + d
231113872 1113873 minus j22 d
21 + d
231113872 1113873
minus 2 j11 + j22( 1113857 d1d2 + d2d3 + d1d3( 1113857
I3 j11 + j22( 1113857 d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ d1 + d2( 1113857 j11j22 minus j12j21( 1113857 minus d1 + d3( 1113857j13j31
I4 minus j11 + j22( 1113857 j11j22 minus j12j21( 1113857 + j11j13j31
(17)
Obviously if j11j22 gt j12j21 (ie aglt 1) thenHi gt 0 Ai gt 0 andCi gt 0 It follows from the RouthndashHurwitzcriterion that the three roots λi1 λi2 and λi3 of φi(λ) 0 allhave negative real parts Moreover if S 0 thene VS⟶infin w⟶ 1 minus bg j11⟶ minus (bg) j12⟶1 j13⟶ 0 j21⟶ b j22⟶ minus g and j31⟶ minus e(1minus (bg)) erefore if bltg then Hi gt 0 Ai gt 0 andCi gt 0
We claim that for each ige 1 there exists a positiveconstant δ such that
Re λi11113864 1113865Re λi21113966 1113967Re λi31113966 1113967le minus δ ige 1 (18)
Let λ μiξ en φi(λ) μ3i ξ3
+ Aiμ2i ξ2
+ Biμiξ +
Ci ≜ 1113957φi(ξ) Since μi⟶infin as i⟶ infin it follows that
limi⟶infin
1113957φi(ξ)
μ3i1113896 1113897 ξ3 + d1 + d2 + d3( 1113857ξ2
+ d1d2 + d2d3 + d1d3( 1113857ξ + d1d2d3 ≜ 1113957φ(ξ)
(19)
Clearly 1113957φ(ξ) 0 has three negative roots minus d1 minus d2 andminus d3 Let dlowast min d1 d2 d31113864 1113865 By continuity one can see thatthere exists a i0 such that the three roots ξi1 ξi2 and ξi3 of1113957φi(ξ) 0 satisfy Re ξi11113864 1113865Re ξi21113864 1113865Re ξi31113864 1113865le minus dlowast2 when ige i0erefore if ige i0 then Re λi11113864 1113865Re λi21113864 1113865Re λi31113864 1113865leminus μidlowast2le minus dlowast2 Let 1113957δ minus max0leilei0 Re λi11113864 1113865Re λi21113864 11138651113864
Re λi31113864 1113865en 1113957δ gt 0 and (18) holds for δ min 1113957δ dlowast21113966 1113967 Sothe positive equilibrium point E3 of (5) is locally asymp-totically stable
In order to obtain the global asymptotic behavior of thesolutions to (5) or (6) we need the following result whichcan be found in [12]
Lemma 1 Let a and b be positive constants Assume thatφψ isin C1[a +infin) ψ(t)ge 0 and φ is bounded from below Ifφprime(t)le minus bψ(t) and ψprime(t) is bounded from above in [a +infin)then limt⟶infinψ(t) 0
Theorem 3
(1) -e positive equilibrium E3 of (5) is globally as-ymptotically stable if aglt 1 andeg + agslt egslt eg + s
(2) -e semitrivial equilibrium E2 of (5) is globally as-ymptotically stable if 1lt (1 minus ab)(b minus g)lt bg
Proof Let (u v w) be the unique positive solution of (5)Estimates similar to eorem 21 in [15] and eorem
A2 in [20] show
u(middot t)C2+α(Ω)
v(middot t)C2+α(Ω)
u(middot t)C2+α(Ω)leC forallt ge 1
(20)
where α isin (0 1) and C does not depend on t
(1) Define
V(u v w) 1113946Ω
u minus u minus u lnu
u1113874 1113875 + λ v minus v minus v ln
v
v1113874 11138751113876
+ ρ w minus w minus w lnw
w1113874 11138751113877dx
(21)
where λ (e + as)eg and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if andonly if u u v v andw w e time derivativeof V(u v w) for (5) satisfies that
dV(u v w)
dt minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
2+
(e + as)
s
v
u
1113971
(u minus u) minus
s(e + as)u
v
1113970
(v minus v)⎛⎝ ⎞⎠
2⎧⎪⎨
⎪⎩
⎫⎪⎬
⎪⎭dx
le minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
21113896 1113897dx
(22)
Complexity 5
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
where
a BMmat
SA
cMmat
A
b RA
M2mat
g A + Mjuv
Mmat
s T
Mmat
r U
C
e V
S
(4)
We can see that e is the only parameter depending on S
in system (3)Most works on cannibalism adopt a McKendrickndashvon
Foerster age-structured model [2ndash4] but the model isusually rewritten as an ODE system or nonlinear Volterraintegral equations [4 5] In 1995 Kohlmeier and Ebenhoh[6] studied a two-dimensional ODE model without anystructure and they obtained that in some cases cannibalismcan lead to a higher long term predator stock size en vanden Bosch and Gabriel [7] found that cannibalism canstabilize a predator-prey system in a structured model wherethe oscillations are due to age structure
Magnusson [1] discussed model (1) which is in someways a simplification of the system studied by van den Boschand Gabriel in [7] Magnusson made two simplificationsFirstly it is assumed that all juveniles are vulnerable topredation by the adults Secondly instantaneous maturationinto the adult class is proportional to the present juvenilebiomass ie a constant per capita rate of maturation and
making this simplifying assumption means that any oscil-lations that may occur are not caused by a delay inherent inthe system Moreover the stability and Hopf bifurcation ofsolutions for system (3) were studied in [1] e authorobtained the following conclusions On one hand if themortality rate of juveniles is low andor the recruitment rateto the mature population is high then there is a stableequilibrium with all three population sizes as positive Onthe other hand if the mortality rate of juveniles is high andor the recruitment rate to the mature population is low thenthe equilibrium will be stable for low levels of cannibalismbut a loss of stability by a Hopf bifurcation will take place asthe level of cannibalism increases
As we all know the growth of biological populationdepends not only on time but also on spatial distributionSpatial species interaction includes the self-diffusion whichis the natural dispersive force of movement of individualand the cross-diffusion that is the population fluxes of onespecies due to the presence of other species [8ndash16] ere-fore taking into account the effect of competition for re-sources on species growth law we are naturally led to thefollowing weakly coupled reaction-diffusion model
ut d1Δu minus u + v + auv + uw x isin Ω tgt 0
vt d2Δv + bu minus gv minus uv x isin Ω tgt 0
wt d3Δw + sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(5)
and the Shigesada-Kawasaki-Teramoto model with stronglycoupled cross-diffusion
ut Δ d1u + α11u2 + α12uv + α13uw( 1113857 minus u + v + auv + uw x isin Ω tgt 0
vt Δ d2v + α21uv + α22v2 + α23vw( 1113857 + bu minus gv minus uv x isin Ω tgt 0
wt Δ d3w + α31uw + α32vw + α33w2( 1113857 + sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(6)
where Ω sub Rn is a bounded domain with smooth boundaryzΩ and η is the outward unit normal vector of the boundaryzΩ zη zzη e coefficients di(i 1 2 3) are the diffu-sion rates of u v andw αii(i 1 2 3) are referred as self-diffusion pressures and αij(ine j i j 1 2 3) are cross-diffusion coefficients which may be positive negative or
zero [17] e functions u0 v0 andw0 are nonnegativefunctions which are not identically zero
Very recently Zhang et al [18] found that the positiveequilibrium of (3) with r 0 can undergo stability switch(from stable to unstable to stable or from unstable to stableto unstable) with the change of the cannibalization rate
2 Complexity
eir results indicate that large cannibalization rate canmake the positive equilibrium globally stable although itsstability would change with the increase of the rate In factan important research subject for cannibalism models is thestabilizingdestabilizing effect of cannibalism [1 6 19] Forthis we need to compare the effect of cannibalism on thedynamic behavior for the ODE system the semilinear re-action-diffusion system and the quasi-linear cross-diffusionsystem
In this paper we first prove that stability properties ofequilibria for the ODE model (3) and the semilinear reac-tion-diffusion model (5) is similar but under suitableconditions on reaction coefficients cross-diffusion-drivenTuring instability in the quasi-linear model (6) occurs It isfound that the cross diffusion rate α13 is a decisive factor ofdestabilizing positive steady state that is cannibalism has nolonger a stabilizing effect en the uniform boundednessand the global existence of time-varying solutions for thecross-diffusion system (6) are investigated by using theenergy estimates and GagliardondashNirenberg-type inequalitieswhen the space dimension is one Finally some criteria onthe global asymptotic stability of the positive equilibriumpoint for (6) are given by Lyapunov function e obtainedresults indicate that for any cannibalism rate e undercertain conditions on the other reaction coefficients themodel has no nonconstant positive steady state if the dif-fusion matrix is positive definite and the self-diffusion co-efficients are large enough
Moreover we in [14] discussed another cross-diffusionmodel
ut minus d1Δu minus u + v + auv + uw x isin Ω tgt 0
vt minus Δ d2v +d4v
ε + u21113888 1113889 bu minus gv minus uv x isin Ω tgt 0
wt minus d3Δw sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(7)
where d4 is a cross-diffusion coefficient and ε is a positiveconstant (please refer to [12]) We proved that ifa b g s r e ε d1 d2 and d3 are fixed such that0lt εlt ε0 aglt 1 rgt s and (9) (see Section 2) hold then thereexists a positive constant dlowast4 such that (7) has at least onenonconstant positive steady state for d4 gedlowast4 is impliesthat the cross-diffusion rate is the decisive factor of
destabilization on the constant positive steady state andtherefore cannibalism is an auxiliary destabilizing forceRecently in another paper we detailedly describe the localstructure of the nonconstant steady states and discuss thestability and instability of the steady state bifurcation
2 Linearization Analysis
In this section according to the linearization analysis andRouthndashHurwitz criterion we focus on discussing the sta-bility of the reaction-diffusion system (5) and cross-diffusionsystem (6) To this end we first introduce the stability of theODE system (3)
21 ODE Model (3) Obviously problem (3) has trivialequilibrium E0(0 0 0) semitrivial equilibrium E1(0 0 sr)and E2((g minus b)(ab minus 1) (g minus b)(ag minus 1) 0) if glt blt 1aor ggt bgt 1a Moreover if r 0 bltg + ((s(1 minus ag))(e + as)) then a positive equilibrium point is given byE3(u v w) where
u s
e
v bs
eg + s
w e(g minus b) + s(1 minus ab)
eg + s
(8)
If rne 0 andbr + gs minus grgt 0
s + eg + r(1 minus ab)gt 0
s(1 minus ab) + e(g minus b)gt 0
⎧⎪⎪⎨
⎪⎪⎩(9)
then a positive equilibrium point is uniquely given by1113957u (1113957u 1113957v 1113957w) where
1113957u α +
α2 + 4eβ
1113968
2e
1113957v b1113957u
g + 1113957u
1113957w s minus e1113957u
r
α abr + s minus r minus eg
β br + gs minus gr
(10)
In fact the stability of these nonnegative equilibria in (3)has been obtained in [1] as follows
(1) E0 is unconditionally unstable(2) E1 is locally asymptotically stable if slt r and is
unstable if sgt r(3) E2 is locally asymptotically stable if glt blt 1a and is
unstable if bltg + ((s(1 minus ag))(e + as))
Complexity 3
(4)
(a) If aglt 1 then E3 is locally asymptotically stable(b) If aggt 1 S 0 (ie e⟶infin) and bltg then E3
is locally asymptotically stable(c) If aggt 1 Sne 0 (ie eneinfin) bltg and ablt 1 then
there exists elowast such that E3 is locally asymp-totically stable when egt elowast and is unstable whenelt elowast
Now we give the stability of 1113957u with respect to model (3)
Theorem 1 -e positive equilibrium 1113957u of (3) is locally as-ymptotically stable if aglt 1
Proof e Jacobian matrix of (3) to the generic us (us
vs ws) reads
J us( 1113857
j11 j12 j13
j21 j22 j23
j31 j32 j33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (11)
wherej11 minus 1 + avs + ws
j12 1 + aus
j13 us
j21 b minus vs
j22 minus g minus us
j23 0
j31 minus ews
j32 0
j33 s minus 2rws minus eus
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(12)
A direct calculation yields that the characteristic equa-tion of J(1113957u) is
φ(λ) |λI minus J| λ3 + α1λ2
+ α2λ + α3 0 (13)
with
α1 11113957u
g1113957u + 1113957v + +1113957u2
+ r1113957u1113957w1113872 1113873gt 0
α2 11113957u
(1 minus ag)1113957u1113957v + r1113957w(1113957v + g1113957u) +(e + r)1113957u2
1113957w1113872 1113873
α3 11113957u
e1113957w1113957u2(g + 1113957u) + r(1 minus ag)1113957u1113957v1113957w1113872 1113873
α1α2 minus α3 r1113957w1113957u2
+ (1 minus ag)1113957v + 2gr1113957w + re1113957w2
+ r2
1113957w2
1113872 11138731113957u
+ rg2
1113957w + e1113957v1113957w + 2r1113957v1113957w + gr2
1113957w2
+(1 minus ag)g1113957v +r1113957w1113957v2
1113957u2 +11113957u
middot (1 minus ag)1113957v2
+ r2
1113957w21113957v + 2gr1113957v1113957w1113872 1113873
(14)
It is easy to see that α3 gt 0 and α1α2 minus α3 gt 0 thanks toaglt 1erefore by RouthndashHurwitz criterion we know that(1113957u 1113957v 1113957w) is locally asymptotically stable
Notice that the unstable equilibrium points of (3) arealso unstable for (5) and (6) erefore for systems (5) and(6) we only discuss the stability of the equilibrium pointswhich are stable for (3)
22 Weakly Coupled Reaction-Diffusion System (5) Let 0
μ1 lt μ2 lt μ3 lt middot middot middot be the eigenvalues of the operator minus Δ on Ωwith the homogeneous Neumann boundary condition andlet E(μi) be the eigenspace corresponding to μi in H1(Ω)Let X be the closure of [C1(Ω)]3 in [H1(Ω)]3ϕij j 1 2 dimE(μi)1113966 1113967 be an orthonormal basis of
E(μi) and let Xij cϕij c isin R31113966 1113967 en
X oplus+infin
i1Xi
Xi oplusdimE μi( )
j1Xij
(15)
For system (5) by the linearization analysis and somesimilar arguments to the proof of eorem 2 andeorem 3in [12] we can obtain the following two theorems
Theorem 2
(1) -e semitrivial equilibrium E1 of (5) is locally as-ymptotically stable if slt r
(2) -e semitrivial equilibrium E2 of (5) is locally as-ymptotically stable if glt blt 1a
(3) -e positive equilibrium E3 of (5) is locally asymp-totically stable either aglt 1 or aggt 1 S 0 (iee⟶infin) and bltg
Proof We only prove (3) e proof of (1) and (2) is similarto (3) so we omit it here Let u (u v w)D
diag(d1 d2 d3) and L DΔ + J(E3) where j11 minus (be(eg + s))lt 0 j12 (e + as)egt 0 j13 ugt 0 j21 (beg(eg + s))gt 0 j22 minus (g + u)lt 0 j23 0 j31 minus ewlt 0
and j32 j33 0 e linearization of (5) at E3 is ut LuFor each ige 1 Xi is invariant under the operatorL and λ isan eigenvalue of L if and only if it is an eigenvalue of thematrix minus μiD + J(E3) for some ige 1 in which case there is an
eigenvector in Xi Denote the characteristic polynomial ofminus μiD + J(E3) by φi(λ) λ3 + Aiλ
2 + Biλ + Ci whereAi μi d1 + d2 + d3( 1113857 minus j11 + j22( 1113857
Bi μ2i d1d2 + d2d3 + d1d3( 1113857 minus μi d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ j11j22 minus j12j21 minus j13j31
Ci μ3i d1d2d3 minus μ2i d1d3a22 + d2d3j11( 1113857
+ μi d3j11j22 minus d3j12j21 minus d2j13j31( 1113857 + j22j13j31
(16)
A straightforward computation gives Hi AiBi minus Ci
I1μ3i + I2μ2i + I3μi + I4 where
4 Complexity
I1 d21 d2 + d3( 1113857 + d
22 d1 + d3( 1113857 + d
23 d1 + d2( 1113857 + 2d1d2d3
I2 minus j11 d22 + d
231113872 1113873 minus j22 d
21 + d
231113872 1113873
minus 2 j11 + j22( 1113857 d1d2 + d2d3 + d1d3( 1113857
I3 j11 + j22( 1113857 d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ d1 + d2( 1113857 j11j22 minus j12j21( 1113857 minus d1 + d3( 1113857j13j31
I4 minus j11 + j22( 1113857 j11j22 minus j12j21( 1113857 + j11j13j31
(17)
Obviously if j11j22 gt j12j21 (ie aglt 1) thenHi gt 0 Ai gt 0 andCi gt 0 It follows from the RouthndashHurwitzcriterion that the three roots λi1 λi2 and λi3 of φi(λ) 0 allhave negative real parts Moreover if S 0 thene VS⟶infin w⟶ 1 minus bg j11⟶ minus (bg) j12⟶1 j13⟶ 0 j21⟶ b j22⟶ minus g and j31⟶ minus e(1minus (bg)) erefore if bltg then Hi gt 0 Ai gt 0 andCi gt 0
We claim that for each ige 1 there exists a positiveconstant δ such that
Re λi11113864 1113865Re λi21113966 1113967Re λi31113966 1113967le minus δ ige 1 (18)
Let λ μiξ en φi(λ) μ3i ξ3
+ Aiμ2i ξ2
+ Biμiξ +
Ci ≜ 1113957φi(ξ) Since μi⟶infin as i⟶ infin it follows that
limi⟶infin
1113957φi(ξ)
μ3i1113896 1113897 ξ3 + d1 + d2 + d3( 1113857ξ2
+ d1d2 + d2d3 + d1d3( 1113857ξ + d1d2d3 ≜ 1113957φ(ξ)
(19)
Clearly 1113957φ(ξ) 0 has three negative roots minus d1 minus d2 andminus d3 Let dlowast min d1 d2 d31113864 1113865 By continuity one can see thatthere exists a i0 such that the three roots ξi1 ξi2 and ξi3 of1113957φi(ξ) 0 satisfy Re ξi11113864 1113865Re ξi21113864 1113865Re ξi31113864 1113865le minus dlowast2 when ige i0erefore if ige i0 then Re λi11113864 1113865Re λi21113864 1113865Re λi31113864 1113865leminus μidlowast2le minus dlowast2 Let 1113957δ minus max0leilei0 Re λi11113864 1113865Re λi21113864 11138651113864
Re λi31113864 1113865en 1113957δ gt 0 and (18) holds for δ min 1113957δ dlowast21113966 1113967 Sothe positive equilibrium point E3 of (5) is locally asymp-totically stable
In order to obtain the global asymptotic behavior of thesolutions to (5) or (6) we need the following result whichcan be found in [12]
Lemma 1 Let a and b be positive constants Assume thatφψ isin C1[a +infin) ψ(t)ge 0 and φ is bounded from below Ifφprime(t)le minus bψ(t) and ψprime(t) is bounded from above in [a +infin)then limt⟶infinψ(t) 0
Theorem 3
(1) -e positive equilibrium E3 of (5) is globally as-ymptotically stable if aglt 1 andeg + agslt egslt eg + s
(2) -e semitrivial equilibrium E2 of (5) is globally as-ymptotically stable if 1lt (1 minus ab)(b minus g)lt bg
Proof Let (u v w) be the unique positive solution of (5)Estimates similar to eorem 21 in [15] and eorem
A2 in [20] show
u(middot t)C2+α(Ω)
v(middot t)C2+α(Ω)
u(middot t)C2+α(Ω)leC forallt ge 1
(20)
where α isin (0 1) and C does not depend on t
(1) Define
V(u v w) 1113946Ω
u minus u minus u lnu
u1113874 1113875 + λ v minus v minus v ln
v
v1113874 11138751113876
+ ρ w minus w minus w lnw
w1113874 11138751113877dx
(21)
where λ (e + as)eg and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if andonly if u u v v andw w e time derivativeof V(u v w) for (5) satisfies that
dV(u v w)
dt minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
2+
(e + as)
s
v
u
1113971
(u minus u) minus
s(e + as)u
v
1113970
(v minus v)⎛⎝ ⎞⎠
2⎧⎪⎨
⎪⎩
⎫⎪⎬
⎪⎭dx
le minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
21113896 1113897dx
(22)
Complexity 5
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
eir results indicate that large cannibalization rate canmake the positive equilibrium globally stable although itsstability would change with the increase of the rate In factan important research subject for cannibalism models is thestabilizingdestabilizing effect of cannibalism [1 6 19] Forthis we need to compare the effect of cannibalism on thedynamic behavior for the ODE system the semilinear re-action-diffusion system and the quasi-linear cross-diffusionsystem
In this paper we first prove that stability properties ofequilibria for the ODE model (3) and the semilinear reac-tion-diffusion model (5) is similar but under suitableconditions on reaction coefficients cross-diffusion-drivenTuring instability in the quasi-linear model (6) occurs It isfound that the cross diffusion rate α13 is a decisive factor ofdestabilizing positive steady state that is cannibalism has nolonger a stabilizing effect en the uniform boundednessand the global existence of time-varying solutions for thecross-diffusion system (6) are investigated by using theenergy estimates and GagliardondashNirenberg-type inequalitieswhen the space dimension is one Finally some criteria onthe global asymptotic stability of the positive equilibriumpoint for (6) are given by Lyapunov function e obtainedresults indicate that for any cannibalism rate e undercertain conditions on the other reaction coefficients themodel has no nonconstant positive steady state if the dif-fusion matrix is positive definite and the self-diffusion co-efficients are large enough
Moreover we in [14] discussed another cross-diffusionmodel
ut minus d1Δu minus u + v + auv + uw x isin Ω tgt 0
vt minus Δ d2v +d4v
ε + u21113888 1113889 bu minus gv minus uv x isin Ω tgt 0
wt minus d3Δw sw minus rw2 minus euw x isin Ω tgt 0
zηu zηv zηw 0 x isin zΩ tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(7)
where d4 is a cross-diffusion coefficient and ε is a positiveconstant (please refer to [12]) We proved that ifa b g s r e ε d1 d2 and d3 are fixed such that0lt εlt ε0 aglt 1 rgt s and (9) (see Section 2) hold then thereexists a positive constant dlowast4 such that (7) has at least onenonconstant positive steady state for d4 gedlowast4 is impliesthat the cross-diffusion rate is the decisive factor of
destabilization on the constant positive steady state andtherefore cannibalism is an auxiliary destabilizing forceRecently in another paper we detailedly describe the localstructure of the nonconstant steady states and discuss thestability and instability of the steady state bifurcation
2 Linearization Analysis
In this section according to the linearization analysis andRouthndashHurwitz criterion we focus on discussing the sta-bility of the reaction-diffusion system (5) and cross-diffusionsystem (6) To this end we first introduce the stability of theODE system (3)
21 ODE Model (3) Obviously problem (3) has trivialequilibrium E0(0 0 0) semitrivial equilibrium E1(0 0 sr)and E2((g minus b)(ab minus 1) (g minus b)(ag minus 1) 0) if glt blt 1aor ggt bgt 1a Moreover if r 0 bltg + ((s(1 minus ag))(e + as)) then a positive equilibrium point is given byE3(u v w) where
u s
e
v bs
eg + s
w e(g minus b) + s(1 minus ab)
eg + s
(8)
If rne 0 andbr + gs minus grgt 0
s + eg + r(1 minus ab)gt 0
s(1 minus ab) + e(g minus b)gt 0
⎧⎪⎪⎨
⎪⎪⎩(9)
then a positive equilibrium point is uniquely given by1113957u (1113957u 1113957v 1113957w) where
1113957u α +
α2 + 4eβ
1113968
2e
1113957v b1113957u
g + 1113957u
1113957w s minus e1113957u
r
α abr + s minus r minus eg
β br + gs minus gr
(10)
In fact the stability of these nonnegative equilibria in (3)has been obtained in [1] as follows
(1) E0 is unconditionally unstable(2) E1 is locally asymptotically stable if slt r and is
unstable if sgt r(3) E2 is locally asymptotically stable if glt blt 1a and is
unstable if bltg + ((s(1 minus ag))(e + as))
Complexity 3
(4)
(a) If aglt 1 then E3 is locally asymptotically stable(b) If aggt 1 S 0 (ie e⟶infin) and bltg then E3
is locally asymptotically stable(c) If aggt 1 Sne 0 (ie eneinfin) bltg and ablt 1 then
there exists elowast such that E3 is locally asymp-totically stable when egt elowast and is unstable whenelt elowast
Now we give the stability of 1113957u with respect to model (3)
Theorem 1 -e positive equilibrium 1113957u of (3) is locally as-ymptotically stable if aglt 1
Proof e Jacobian matrix of (3) to the generic us (us
vs ws) reads
J us( 1113857
j11 j12 j13
j21 j22 j23
j31 j32 j33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (11)
wherej11 minus 1 + avs + ws
j12 1 + aus
j13 us
j21 b minus vs
j22 minus g minus us
j23 0
j31 minus ews
j32 0
j33 s minus 2rws minus eus
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(12)
A direct calculation yields that the characteristic equa-tion of J(1113957u) is
φ(λ) |λI minus J| λ3 + α1λ2
+ α2λ + α3 0 (13)
with
α1 11113957u
g1113957u + 1113957v + +1113957u2
+ r1113957u1113957w1113872 1113873gt 0
α2 11113957u
(1 minus ag)1113957u1113957v + r1113957w(1113957v + g1113957u) +(e + r)1113957u2
1113957w1113872 1113873
α3 11113957u
e1113957w1113957u2(g + 1113957u) + r(1 minus ag)1113957u1113957v1113957w1113872 1113873
α1α2 minus α3 r1113957w1113957u2
+ (1 minus ag)1113957v + 2gr1113957w + re1113957w2
+ r2
1113957w2
1113872 11138731113957u
+ rg2
1113957w + e1113957v1113957w + 2r1113957v1113957w + gr2
1113957w2
+(1 minus ag)g1113957v +r1113957w1113957v2
1113957u2 +11113957u
middot (1 minus ag)1113957v2
+ r2
1113957w21113957v + 2gr1113957v1113957w1113872 1113873
(14)
It is easy to see that α3 gt 0 and α1α2 minus α3 gt 0 thanks toaglt 1erefore by RouthndashHurwitz criterion we know that(1113957u 1113957v 1113957w) is locally asymptotically stable
Notice that the unstable equilibrium points of (3) arealso unstable for (5) and (6) erefore for systems (5) and(6) we only discuss the stability of the equilibrium pointswhich are stable for (3)
22 Weakly Coupled Reaction-Diffusion System (5) Let 0
μ1 lt μ2 lt μ3 lt middot middot middot be the eigenvalues of the operator minus Δ on Ωwith the homogeneous Neumann boundary condition andlet E(μi) be the eigenspace corresponding to μi in H1(Ω)Let X be the closure of [C1(Ω)]3 in [H1(Ω)]3ϕij j 1 2 dimE(μi)1113966 1113967 be an orthonormal basis of
E(μi) and let Xij cϕij c isin R31113966 1113967 en
X oplus+infin
i1Xi
Xi oplusdimE μi( )
j1Xij
(15)
For system (5) by the linearization analysis and somesimilar arguments to the proof of eorem 2 andeorem 3in [12] we can obtain the following two theorems
Theorem 2
(1) -e semitrivial equilibrium E1 of (5) is locally as-ymptotically stable if slt r
(2) -e semitrivial equilibrium E2 of (5) is locally as-ymptotically stable if glt blt 1a
(3) -e positive equilibrium E3 of (5) is locally asymp-totically stable either aglt 1 or aggt 1 S 0 (iee⟶infin) and bltg
Proof We only prove (3) e proof of (1) and (2) is similarto (3) so we omit it here Let u (u v w)D
diag(d1 d2 d3) and L DΔ + J(E3) where j11 minus (be(eg + s))lt 0 j12 (e + as)egt 0 j13 ugt 0 j21 (beg(eg + s))gt 0 j22 minus (g + u)lt 0 j23 0 j31 minus ewlt 0
and j32 j33 0 e linearization of (5) at E3 is ut LuFor each ige 1 Xi is invariant under the operatorL and λ isan eigenvalue of L if and only if it is an eigenvalue of thematrix minus μiD + J(E3) for some ige 1 in which case there is an
eigenvector in Xi Denote the characteristic polynomial ofminus μiD + J(E3) by φi(λ) λ3 + Aiλ
2 + Biλ + Ci whereAi μi d1 + d2 + d3( 1113857 minus j11 + j22( 1113857
Bi μ2i d1d2 + d2d3 + d1d3( 1113857 minus μi d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ j11j22 minus j12j21 minus j13j31
Ci μ3i d1d2d3 minus μ2i d1d3a22 + d2d3j11( 1113857
+ μi d3j11j22 minus d3j12j21 minus d2j13j31( 1113857 + j22j13j31
(16)
A straightforward computation gives Hi AiBi minus Ci
I1μ3i + I2μ2i + I3μi + I4 where
4 Complexity
I1 d21 d2 + d3( 1113857 + d
22 d1 + d3( 1113857 + d
23 d1 + d2( 1113857 + 2d1d2d3
I2 minus j11 d22 + d
231113872 1113873 minus j22 d
21 + d
231113872 1113873
minus 2 j11 + j22( 1113857 d1d2 + d2d3 + d1d3( 1113857
I3 j11 + j22( 1113857 d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ d1 + d2( 1113857 j11j22 minus j12j21( 1113857 minus d1 + d3( 1113857j13j31
I4 minus j11 + j22( 1113857 j11j22 minus j12j21( 1113857 + j11j13j31
(17)
Obviously if j11j22 gt j12j21 (ie aglt 1) thenHi gt 0 Ai gt 0 andCi gt 0 It follows from the RouthndashHurwitzcriterion that the three roots λi1 λi2 and λi3 of φi(λ) 0 allhave negative real parts Moreover if S 0 thene VS⟶infin w⟶ 1 minus bg j11⟶ minus (bg) j12⟶1 j13⟶ 0 j21⟶ b j22⟶ minus g and j31⟶ minus e(1minus (bg)) erefore if bltg then Hi gt 0 Ai gt 0 andCi gt 0
We claim that for each ige 1 there exists a positiveconstant δ such that
Re λi11113864 1113865Re λi21113966 1113967Re λi31113966 1113967le minus δ ige 1 (18)
Let λ μiξ en φi(λ) μ3i ξ3
+ Aiμ2i ξ2
+ Biμiξ +
Ci ≜ 1113957φi(ξ) Since μi⟶infin as i⟶ infin it follows that
limi⟶infin
1113957φi(ξ)
μ3i1113896 1113897 ξ3 + d1 + d2 + d3( 1113857ξ2
+ d1d2 + d2d3 + d1d3( 1113857ξ + d1d2d3 ≜ 1113957φ(ξ)
(19)
Clearly 1113957φ(ξ) 0 has three negative roots minus d1 minus d2 andminus d3 Let dlowast min d1 d2 d31113864 1113865 By continuity one can see thatthere exists a i0 such that the three roots ξi1 ξi2 and ξi3 of1113957φi(ξ) 0 satisfy Re ξi11113864 1113865Re ξi21113864 1113865Re ξi31113864 1113865le minus dlowast2 when ige i0erefore if ige i0 then Re λi11113864 1113865Re λi21113864 1113865Re λi31113864 1113865leminus μidlowast2le minus dlowast2 Let 1113957δ minus max0leilei0 Re λi11113864 1113865Re λi21113864 11138651113864
Re λi31113864 1113865en 1113957δ gt 0 and (18) holds for δ min 1113957δ dlowast21113966 1113967 Sothe positive equilibrium point E3 of (5) is locally asymp-totically stable
In order to obtain the global asymptotic behavior of thesolutions to (5) or (6) we need the following result whichcan be found in [12]
Lemma 1 Let a and b be positive constants Assume thatφψ isin C1[a +infin) ψ(t)ge 0 and φ is bounded from below Ifφprime(t)le minus bψ(t) and ψprime(t) is bounded from above in [a +infin)then limt⟶infinψ(t) 0
Theorem 3
(1) -e positive equilibrium E3 of (5) is globally as-ymptotically stable if aglt 1 andeg + agslt egslt eg + s
(2) -e semitrivial equilibrium E2 of (5) is globally as-ymptotically stable if 1lt (1 minus ab)(b minus g)lt bg
Proof Let (u v w) be the unique positive solution of (5)Estimates similar to eorem 21 in [15] and eorem
A2 in [20] show
u(middot t)C2+α(Ω)
v(middot t)C2+α(Ω)
u(middot t)C2+α(Ω)leC forallt ge 1
(20)
where α isin (0 1) and C does not depend on t
(1) Define
V(u v w) 1113946Ω
u minus u minus u lnu
u1113874 1113875 + λ v minus v minus v ln
v
v1113874 11138751113876
+ ρ w minus w minus w lnw
w1113874 11138751113877dx
(21)
where λ (e + as)eg and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if andonly if u u v v andw w e time derivativeof V(u v w) for (5) satisfies that
dV(u v w)
dt minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
2+
(e + as)
s
v
u
1113971
(u minus u) minus
s(e + as)u
v
1113970
(v minus v)⎛⎝ ⎞⎠
2⎧⎪⎨
⎪⎩
⎫⎪⎬
⎪⎭dx
le minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
21113896 1113897dx
(22)
Complexity 5
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
(4)
(a) If aglt 1 then E3 is locally asymptotically stable(b) If aggt 1 S 0 (ie e⟶infin) and bltg then E3
is locally asymptotically stable(c) If aggt 1 Sne 0 (ie eneinfin) bltg and ablt 1 then
there exists elowast such that E3 is locally asymp-totically stable when egt elowast and is unstable whenelt elowast
Now we give the stability of 1113957u with respect to model (3)
Theorem 1 -e positive equilibrium 1113957u of (3) is locally as-ymptotically stable if aglt 1
Proof e Jacobian matrix of (3) to the generic us (us
vs ws) reads
J us( 1113857
j11 j12 j13
j21 j22 j23
j31 j32 j33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (11)
wherej11 minus 1 + avs + ws
j12 1 + aus
j13 us
j21 b minus vs
j22 minus g minus us
j23 0
j31 minus ews
j32 0
j33 s minus 2rws minus eus
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(12)
A direct calculation yields that the characteristic equa-tion of J(1113957u) is
φ(λ) |λI minus J| λ3 + α1λ2
+ α2λ + α3 0 (13)
with
α1 11113957u
g1113957u + 1113957v + +1113957u2
+ r1113957u1113957w1113872 1113873gt 0
α2 11113957u
(1 minus ag)1113957u1113957v + r1113957w(1113957v + g1113957u) +(e + r)1113957u2
1113957w1113872 1113873
α3 11113957u
e1113957w1113957u2(g + 1113957u) + r(1 minus ag)1113957u1113957v1113957w1113872 1113873
α1α2 minus α3 r1113957w1113957u2
+ (1 minus ag)1113957v + 2gr1113957w + re1113957w2
+ r2
1113957w2
1113872 11138731113957u
+ rg2
1113957w + e1113957v1113957w + 2r1113957v1113957w + gr2
1113957w2
+(1 minus ag)g1113957v +r1113957w1113957v2
1113957u2 +11113957u
middot (1 minus ag)1113957v2
+ r2
1113957w21113957v + 2gr1113957v1113957w1113872 1113873
(14)
It is easy to see that α3 gt 0 and α1α2 minus α3 gt 0 thanks toaglt 1erefore by RouthndashHurwitz criterion we know that(1113957u 1113957v 1113957w) is locally asymptotically stable
Notice that the unstable equilibrium points of (3) arealso unstable for (5) and (6) erefore for systems (5) and(6) we only discuss the stability of the equilibrium pointswhich are stable for (3)
22 Weakly Coupled Reaction-Diffusion System (5) Let 0
μ1 lt μ2 lt μ3 lt middot middot middot be the eigenvalues of the operator minus Δ on Ωwith the homogeneous Neumann boundary condition andlet E(μi) be the eigenspace corresponding to μi in H1(Ω)Let X be the closure of [C1(Ω)]3 in [H1(Ω)]3ϕij j 1 2 dimE(μi)1113966 1113967 be an orthonormal basis of
E(μi) and let Xij cϕij c isin R31113966 1113967 en
X oplus+infin
i1Xi
Xi oplusdimE μi( )
j1Xij
(15)
For system (5) by the linearization analysis and somesimilar arguments to the proof of eorem 2 andeorem 3in [12] we can obtain the following two theorems
Theorem 2
(1) -e semitrivial equilibrium E1 of (5) is locally as-ymptotically stable if slt r
(2) -e semitrivial equilibrium E2 of (5) is locally as-ymptotically stable if glt blt 1a
(3) -e positive equilibrium E3 of (5) is locally asymp-totically stable either aglt 1 or aggt 1 S 0 (iee⟶infin) and bltg
Proof We only prove (3) e proof of (1) and (2) is similarto (3) so we omit it here Let u (u v w)D
diag(d1 d2 d3) and L DΔ + J(E3) where j11 minus (be(eg + s))lt 0 j12 (e + as)egt 0 j13 ugt 0 j21 (beg(eg + s))gt 0 j22 minus (g + u)lt 0 j23 0 j31 minus ewlt 0
and j32 j33 0 e linearization of (5) at E3 is ut LuFor each ige 1 Xi is invariant under the operatorL and λ isan eigenvalue of L if and only if it is an eigenvalue of thematrix minus μiD + J(E3) for some ige 1 in which case there is an
eigenvector in Xi Denote the characteristic polynomial ofminus μiD + J(E3) by φi(λ) λ3 + Aiλ
2 + Biλ + Ci whereAi μi d1 + d2 + d3( 1113857 minus j11 + j22( 1113857
Bi μ2i d1d2 + d2d3 + d1d3( 1113857 minus μi d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ j11j22 minus j12j21 minus j13j31
Ci μ3i d1d2d3 minus μ2i d1d3a22 + d2d3j11( 1113857
+ μi d3j11j22 minus d3j12j21 minus d2j13j31( 1113857 + j22j13j31
(16)
A straightforward computation gives Hi AiBi minus Ci
I1μ3i + I2μ2i + I3μi + I4 where
4 Complexity
I1 d21 d2 + d3( 1113857 + d
22 d1 + d3( 1113857 + d
23 d1 + d2( 1113857 + 2d1d2d3
I2 minus j11 d22 + d
231113872 1113873 minus j22 d
21 + d
231113872 1113873
minus 2 j11 + j22( 1113857 d1d2 + d2d3 + d1d3( 1113857
I3 j11 + j22( 1113857 d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ d1 + d2( 1113857 j11j22 minus j12j21( 1113857 minus d1 + d3( 1113857j13j31
I4 minus j11 + j22( 1113857 j11j22 minus j12j21( 1113857 + j11j13j31
(17)
Obviously if j11j22 gt j12j21 (ie aglt 1) thenHi gt 0 Ai gt 0 andCi gt 0 It follows from the RouthndashHurwitzcriterion that the three roots λi1 λi2 and λi3 of φi(λ) 0 allhave negative real parts Moreover if S 0 thene VS⟶infin w⟶ 1 minus bg j11⟶ minus (bg) j12⟶1 j13⟶ 0 j21⟶ b j22⟶ minus g and j31⟶ minus e(1minus (bg)) erefore if bltg then Hi gt 0 Ai gt 0 andCi gt 0
We claim that for each ige 1 there exists a positiveconstant δ such that
Re λi11113864 1113865Re λi21113966 1113967Re λi31113966 1113967le minus δ ige 1 (18)
Let λ μiξ en φi(λ) μ3i ξ3
+ Aiμ2i ξ2
+ Biμiξ +
Ci ≜ 1113957φi(ξ) Since μi⟶infin as i⟶ infin it follows that
limi⟶infin
1113957φi(ξ)
μ3i1113896 1113897 ξ3 + d1 + d2 + d3( 1113857ξ2
+ d1d2 + d2d3 + d1d3( 1113857ξ + d1d2d3 ≜ 1113957φ(ξ)
(19)
Clearly 1113957φ(ξ) 0 has three negative roots minus d1 minus d2 andminus d3 Let dlowast min d1 d2 d31113864 1113865 By continuity one can see thatthere exists a i0 such that the three roots ξi1 ξi2 and ξi3 of1113957φi(ξ) 0 satisfy Re ξi11113864 1113865Re ξi21113864 1113865Re ξi31113864 1113865le minus dlowast2 when ige i0erefore if ige i0 then Re λi11113864 1113865Re λi21113864 1113865Re λi31113864 1113865leminus μidlowast2le minus dlowast2 Let 1113957δ minus max0leilei0 Re λi11113864 1113865Re λi21113864 11138651113864
Re λi31113864 1113865en 1113957δ gt 0 and (18) holds for δ min 1113957δ dlowast21113966 1113967 Sothe positive equilibrium point E3 of (5) is locally asymp-totically stable
In order to obtain the global asymptotic behavior of thesolutions to (5) or (6) we need the following result whichcan be found in [12]
Lemma 1 Let a and b be positive constants Assume thatφψ isin C1[a +infin) ψ(t)ge 0 and φ is bounded from below Ifφprime(t)le minus bψ(t) and ψprime(t) is bounded from above in [a +infin)then limt⟶infinψ(t) 0
Theorem 3
(1) -e positive equilibrium E3 of (5) is globally as-ymptotically stable if aglt 1 andeg + agslt egslt eg + s
(2) -e semitrivial equilibrium E2 of (5) is globally as-ymptotically stable if 1lt (1 minus ab)(b minus g)lt bg
Proof Let (u v w) be the unique positive solution of (5)Estimates similar to eorem 21 in [15] and eorem
A2 in [20] show
u(middot t)C2+α(Ω)
v(middot t)C2+α(Ω)
u(middot t)C2+α(Ω)leC forallt ge 1
(20)
where α isin (0 1) and C does not depend on t
(1) Define
V(u v w) 1113946Ω
u minus u minus u lnu
u1113874 1113875 + λ v minus v minus v ln
v
v1113874 11138751113876
+ ρ w minus w minus w lnw
w1113874 11138751113877dx
(21)
where λ (e + as)eg and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if andonly if u u v v andw w e time derivativeof V(u v w) for (5) satisfies that
dV(u v w)
dt minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
2+
(e + as)
s
v
u
1113971
(u minus u) minus
s(e + as)u
v
1113970
(v minus v)⎛⎝ ⎞⎠
2⎧⎪⎨
⎪⎩
⎫⎪⎬
⎪⎭dx
le minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
21113896 1113897dx
(22)
Complexity 5
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
I1 d21 d2 + d3( 1113857 + d
22 d1 + d3( 1113857 + d
23 d1 + d2( 1113857 + 2d1d2d3
I2 minus j11 d22 + d
231113872 1113873 minus j22 d
21 + d
231113872 1113873
minus 2 j11 + j22( 1113857 d1d2 + d2d3 + d1d3( 1113857
I3 j11 + j22( 1113857 d1j22 + d2j11 + d3j11 + d3j22( 1113857
+ d1 + d2( 1113857 j11j22 minus j12j21( 1113857 minus d1 + d3( 1113857j13j31
I4 minus j11 + j22( 1113857 j11j22 minus j12j21( 1113857 + j11j13j31
(17)
Obviously if j11j22 gt j12j21 (ie aglt 1) thenHi gt 0 Ai gt 0 andCi gt 0 It follows from the RouthndashHurwitzcriterion that the three roots λi1 λi2 and λi3 of φi(λ) 0 allhave negative real parts Moreover if S 0 thene VS⟶infin w⟶ 1 minus bg j11⟶ minus (bg) j12⟶1 j13⟶ 0 j21⟶ b j22⟶ minus g and j31⟶ minus e(1minus (bg)) erefore if bltg then Hi gt 0 Ai gt 0 andCi gt 0
We claim that for each ige 1 there exists a positiveconstant δ such that
Re λi11113864 1113865Re λi21113966 1113967Re λi31113966 1113967le minus δ ige 1 (18)
Let λ μiξ en φi(λ) μ3i ξ3
+ Aiμ2i ξ2
+ Biμiξ +
Ci ≜ 1113957φi(ξ) Since μi⟶infin as i⟶ infin it follows that
limi⟶infin
1113957φi(ξ)
μ3i1113896 1113897 ξ3 + d1 + d2 + d3( 1113857ξ2
+ d1d2 + d2d3 + d1d3( 1113857ξ + d1d2d3 ≜ 1113957φ(ξ)
(19)
Clearly 1113957φ(ξ) 0 has three negative roots minus d1 minus d2 andminus d3 Let dlowast min d1 d2 d31113864 1113865 By continuity one can see thatthere exists a i0 such that the three roots ξi1 ξi2 and ξi3 of1113957φi(ξ) 0 satisfy Re ξi11113864 1113865Re ξi21113864 1113865Re ξi31113864 1113865le minus dlowast2 when ige i0erefore if ige i0 then Re λi11113864 1113865Re λi21113864 1113865Re λi31113864 1113865leminus μidlowast2le minus dlowast2 Let 1113957δ minus max0leilei0 Re λi11113864 1113865Re λi21113864 11138651113864
Re λi31113864 1113865en 1113957δ gt 0 and (18) holds for δ min 1113957δ dlowast21113966 1113967 Sothe positive equilibrium point E3 of (5) is locally asymp-totically stable
In order to obtain the global asymptotic behavior of thesolutions to (5) or (6) we need the following result whichcan be found in [12]
Lemma 1 Let a and b be positive constants Assume thatφψ isin C1[a +infin) ψ(t)ge 0 and φ is bounded from below Ifφprime(t)le minus bψ(t) and ψprime(t) is bounded from above in [a +infin)then limt⟶infinψ(t) 0
Theorem 3
(1) -e positive equilibrium E3 of (5) is globally as-ymptotically stable if aglt 1 andeg + agslt egslt eg + s
(2) -e semitrivial equilibrium E2 of (5) is globally as-ymptotically stable if 1lt (1 minus ab)(b minus g)lt bg
Proof Let (u v w) be the unique positive solution of (5)Estimates similar to eorem 21 in [15] and eorem
A2 in [20] show
u(middot t)C2+α(Ω)
v(middot t)C2+α(Ω)
u(middot t)C2+α(Ω)leC forallt ge 1
(20)
where α isin (0 1) and C does not depend on t
(1) Define
V(u v w) 1113946Ω
u minus u minus u lnu
u1113874 1113875 + λ v minus v minus v ln
v
v1113874 11138751113876
+ ρ w minus w minus w lnw
w1113874 11138751113877dx
(21)
where λ (e + as)eg and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if andonly if u u v v andw w e time derivativeof V(u v w) for (5) satisfies that
dV(u v w)
dt minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
2+
(e + as)
s
v
u
1113971
(u minus u) minus
s(e + as)u
v
1113970
(v minus v)⎛⎝ ⎞⎠
2⎧⎪⎨
⎪⎩
⎫⎪⎬
⎪⎭dx
le minus 1113946Ω
d1u
u2 |nablau|2
+λd2v
v2|nablav|
2+ρd3w
w2 |nablaw|2
1113888 1113889dx
minus1s
1113946Ω
(es minus e minus as)
s
v
u(u minus u)
2+
(e + as)(eg + s minus egs)
eg
u
v(v minus v)
21113896 1113897dx
(22)
Complexity 5
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
From eorem 2 Lemma 1 and (20) we know that
limt⟶infin
1113946Ω
|nablau|2
+|nablav|2
+|nablaw|2
1113872 1113873dx 0 (23)
limt⟶infin
1113946Ω
(u minus u)2dx 0
limt⟶infin
1113946Ω
(v minus v)2dx 0
(24)
It follows from the Poincare inequality that
limt⟶infin
1113946Ω
(u minus 1113954u)2dx 0
limt⟶infin
1113946Ω
(v minus 1113954v)2dx 0
limt⟶infin
1113946Ω
(w minus 1113954w)2dx 0
(25)
where 1113954f 111393810 fdx As |1113954u minus u|2 1113938Ω (1113954u minus u)2dxle
21113938Ω(1113954u minus u)2dx + 21113938Ω(u minus u)2dx from (24) and(25) we have
limt⟶infin
1113954u(t) u
limt⟶infin
1113954v(t) v(26)
erefore there exists a sequence tm1113864 1113865 such that1113954uprime(tm)⟶ 0 as tm⟶infin Since 1113954w(tm)1113864 1113865 isbounded so there exists a subsequence still denotedby 1113954w(tm)1113864 1113865 such that 1113954w(tm)⟶ 1113957w as tm⟶infinFrom the first equation of (5) we have
1113954uprime tm( 1113857 1113946Ω
[(av + w minus 1)(u minus u)
+(au + 1)(v minus v) + u(w minus w)]dx|tm
(27)
Let m⟶infin in the above equation and from (25)we have
limtm⟶infin
1113954w(t) w (28)
On the contrary (20) implies that there exists asubsequence still denoted by tm1113864 1113865 and nonnegativefunctions ulowast vlowast wlowast isin C2(Ω) such that
u middot tm( 1113857 minus ulowastC2(Ω)⟶ 0
v middot tm( 1113857 minus vlowastC2(Ω)⟶ 0
w middot tm( 1113857 minus wlowastC2(Ω)⟶ 0
m⟶infin
(29)
Combining this with (25)ndash(28) one can obtain thatulowast u vlowast v wlowast w and
u middot tm( 1113857 minus u
C2(Ω)⟶ 0
v middot tm( 1113857 minus v
C2(Ω)⟶ 0
w middot tm( 1113857 minus w
C2(Ω)⟶ 0
m⟶infin
(30)
e global asymptotic stability of E3 follows fromthis together with eorem 2
(2) Define
V(u v w) 1113946Ω
u minus u2 minus u2 lnu
u21113888 11138891113890
+ l v minus v2 minus v2 lnv
v21113888 1113889 +
1e
w1113891dx
(31)
where l (1 minus ag)(g(1 minus ab)) and u2 (g minus b)(ab minus 1) v2 (g minus b)(ag minus 1) en
dV(u v w)
dt minus 1113946Ω
d1u2
u2 |nablau|2
+λd2v2
v2|nablav|
21113888 1113889dx minus 1113946
Ω
(1 minus ab)(b minus g) minus 1(b minus g)2
v
uu minus u2( 1113857
21113896
+(1 minus ag)2 b
g(b minus g)(1 minus ab)minus 11113888 1113889
u
vv minus v2( 1113857
2+
r
ew
2
+1
b minus g
v
u
1113970
u minus u2( 1113857 minus (1 minus ag)
u
v
1113970
v minus v2( 11138571113888 1113889
2⎫⎬
⎭dx
(32)
From this (2) can be proved using similar argumentsas in (1)
Remark 1 e stability of 1113957u is demonstrated specifically in[14] that is 1113957u is locally asymptotically stable if aglt 1
23 Strongly Coupled Cross-Diffusion System (6)Comparing Sections 21 and 22 we find that Ei i 1 2 3and 1113957u have the same stability properties in systems (3) and(5) For the sake of convenience we denote nonnegativeequilibria Ei i 1 2 3 and 1113957u by us (us vs ws) Now we
6 Complexity
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
show that the destabilization effect of cross-diffusion onus (us vs ws)
Linearizing system (6) at an equilibrium (us vs ws) wecan obtain
zuzt
(D + P)Δu + Ju x isin Ω tgt 0
zuz]
0 x isin zΩ tgt 0
u(x 0) u0(x) x isin Ω
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(33)
where u (u v w)T D diag(d1 d2 d3) and J is given in(11)
P
p11 p12 p13
p21 p22 p23
p31 p33 p33
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝
⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ (34)
with
p11 2α11us + α12vs + α13ws
p12 α12us
p13 α13us
p21 α21vs
p22 α21us + 2α22vs + α23ws
p23 α23vs
p31 α31ws
p32 α32ws
p33 α31us + α32vs + 2α33ws
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(35)
We denote
L ≔ minus μi(D + P) + J (36)
then the corresponding characteristic polynomial of L is
ϕ λ3 + c1λ2
+ c2λ + c3 (37)
where
c1 (trD + trP)μi minus trJ
c2 β1μ2i + β2μi + β3
c3 det μiP minus J( 1113857 β4μ3i + β5μ
2i + β6μi + β7
(38)
with
β1 d1d2 + d1d3 + d2d3 + d1 p22 + p33( 1113857 + d2 p11 + p33( 1113857 + d3 p11 + p22( 1113857 + M11 + M22 + M33
β2 minus j11 d2 + d3 + p22 + p33( 1113857 minus j22 d1 + d3 + p11 + p33( 1113857 minus j33 d1 + d2 + p11 + p22( 1113857 + p21j12 + p12j21 + p31j13 + p13j31
β3 M22 + M33 + j22j33
β4 det(D) + det(P) + d1 d2p33 + d3p22 + M11( 1113857 + d2M22 + d3M33 + d2d3P11
β5 minus j11 M11 + d2p33 + d3p22 + d2d3( 1113857 + j12 M12 + d3p21( 1113857 + j13 d2p31 minus M13( 1113857
+ j21 d3p12 + M21( 1113857 minus j22 M22 + d1p33 + d3p11 + d1d3( 1113857
+ j31 d2p13 minus M31( 1113857 minus j33 M33 + d1d2 + d1p22 + d2p11( 1113857
β6 p11 + d1( 1113857j22j33 minus p12j21j33 minus p13j22j31 minus p21j12j33 + p22j11j33 minus p22j13j31
+ p23j12j31 minus p31j13j22 + p32j13j21 + p33 + d3( 1113857M33 + d2M22
β7 minus j33M33 + j13j22j31
(39)
where Mij and Mij i j 1 2 3 are cofactors of matrix P
and J respectivelyerefore according to the principle of the linearized
stability ((21] 86) (22] 52)) the local stability ofnonnegative equilibria of model (6) is given below
Theorem 4 Let di and αij i j 1 2 3 be positive constants-en the following statements for system (6) hold
(1) us is locally asymptotically stable if and only if forevery i isin N all the eigenvalues of the linearizationmatrix L have negative real part
(2) us is unstable if and only if there exists an i isin N suchthat the linearization matrix L has at least one ei-genvalue with positive real part
By applying the RouthndashHurwitz criterion or Corollary 22in [23] we have the following stability and instability results
Corollary 1
(1) E1 is locally asymptotically stable if slt r and bltgmhere m min s (r minus s)r rs2(r minus s)
(2) E2 is locally asymptotically stable if glt blt 1a(1 minus ab)(1 minus ag)lt slt e(b minus g))(1 minus ab) and
Complexity 7
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
(ab minus 1)(ag minus 1)d3 + (ab minus 1)(g minus b)α32 + (g minus b)
(ag minus 1)α31 gt 0
(3) E3 is locally asymptotically stable if aglt 1 eα13 lt α31and (g + u)(2wα33 + d3) + uvα32 gt s(uα21 + 2vα22 +
wα23 + d2)
(4) 1113957u is locally asymptotically stable if slt δ ≔ r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
bltg aglt 1and (er)α23 le α21 le α13 le (α31e)le (α21α33eα23)
(5) If aglt 1 and sgtf then there exists a positive con-stant 1113957α13 such that 1113957u is unstable when α13 gt 1113957α13
(6) If aggt 1 then there exists a positive constant 1113957d3 suchthat 1113957u is unstable when d3 gt 1113957d3
Proof We only prove the case of (4) and (5) other cases canbe treated similarly With the help of the Mapleapplication we can evaluate that ci gt 0 i 1 2 3 and c1c2 minus
c3 gt 0 due to bltg aglt 1 slt δ ≔ r(1 minus ab) minus eg+
(abr minus r + eg)2 + 4er(g minus b)
1113969
and (er)α23 lt α21 lt α13 lt(α31e)lt (α21α33eα23) erefore RouthndashHurwitz criterionshows that 1113957u is locally asymptotically stable
On the contrary the constant equilibrium is unstable ifand only if there exists an i isin N such that c3 lt 0 or c1c2 lt c3anks to calculate c1c2 minus c3 is complicated we now onlydiscuss the case of c3 lt 0
In fact c3 det(μiP minus J) β4μ3i + β5μ2i + β6μi+
β7 ≔ C(α13 μi) where β4 gt 0 In order to study whethercross-diffusion has unstable effect we assume that 1113957u is stablein the corresponding self-diffusion system ie aglt 1 whichimplies that β7 minus j331113957v(1 minus ag) + j13j22j31 gt 0 Let 1113957μ1 1113957μ2and 1113957μ3 be the three roots of C(α13 μi) with Re 1113957μ11113864 1113865leRe 1113957μ21113864 1113865leRe 1113957μ31113864 1113865 en 1113957μ11113957μ21113957μ3 minus (β4β1)lt 0 at least one of1113957μ1 1113957μ2 and 1113957μ3 is real and negative and the product of theother two is positive
Now we consider the following limits
C1 ≔ limα13⟶infin
β1α13
21113957w3α23α33 + 21113957uα21α33 + 41113957vα22α33 + 2d3α33 + d3α23( 1113857 1113957w
2
+ 21113957vα32 1113957uα21 + 1113957vα22( 1113857 + d2 d3 + 1113957vα32( 1113857 + d3 1113957uα21 + 21113957vα22( 1113857
C2 ≔ limα13⟶infin
β2α13
(r1113957w minus e1113957u) 1113957u1113957wα21 + 21113957v1113957wα22 + 1113957w2α231113872 1113873
+(21113957u1113957v + g1113957v minus b1113957u)1113957wα32 + 21113957w2(g + u)α33
C3 ≔ limα13⟶infin
β3α13
(s minus 2e1113957u)(g + 1113957u)
(40)
Note that
limα13⟶infin
C α13 ]i( 1113857
α13 μi C1μ
2i + C2μi + C31113872 1113873 (41)
and C1 gt 0 C3 lt 0 since slt 2e1113957u ie sgt r(1 minus ab)minus
eg +
(abr minus r + eg)2 + 4er(g minus b)
1113969
A continuity argumentyields that 1113957μ1 is real and negative Moreover as 1113957μ21113957μ3 gt 0 1113957μ2and 1113957μ3 are real and positive and
limα13⟶infin
1113957μ1 minus C2 minus
C2 minus 4C1C3
1113968
2C1lt 0
limα13⟶infin
1113957μ2 0
limα13⟶infin
1113957μ3 minus C2 +
C2 minus 4C1C3
1113968
2C1gt 0
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(42)
us there exists a positive constant 1113957α13 such that for allα13 gt 1113957α13 the three roots 1113957μ1 1113957μ2 and 1113957μ3 of C(α13 μi) are allreal and satisfy
minus infinlt 1113957μ1 lt 0lt 1113957μ2 lt 1113957μ3
α3 C α13 μi( 1113857lt 0 when μi isin minus infin 1113957μ1( 1113857cup 1113957μ2 1113957μ3( 1113857
α3 C α13 μi( 1113857gt 0 when μi isin 1113957μ1 1113957μ2( 1113857cup 1113957μ3 +infin( 1113857
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
(43)
erefore the characteristic equation ϕ 0 has at leastone positive eigenvalue when μi isin (1113957μ2 1113957μ3)
Remark 2 Remark 1 and conclusion (5) of Corollary 1indicate that if aglt 1 and
sgtf the large cross-diffusion
rate α13 has destabilizing effect for positive equilibrium point(1113957u 1113957v 1113957w) is means that under suitable conditions onreaction coefficients cross-diffusion-driven Turing insta-bility occurs if the cross-diffusion rate is sufficiently large
To demonstrate the results of stability and instability for1113957u we give the following examples
Example 1 Assume that the spatial domain Ω [0 10π]
(1) Let
8 Complexity
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
α11 α12 α21 α22 α23 α32 1
α13 12
α31 3
α33 4
a 05
b 1
g 15
s 3
e 2
r 4
d1 3
d2 3
d3 2
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(44)
en the equilibrium point (1113957u 1113957v 1113957w) (0725
0326 0388) c1 5809gt 0 c2 10163gt 0 c3
5082gt 0 and c1c2 minus c3 53959gt 0 From Corol-lary 1 (4) 1113957u is locally asymptotically stable
(2) Let
α11 α12 α21 α22 α23 α31 α32 α33 1
d1 3
d2 3
d3 2
a 05
b 13
g 15
s 3
e 5
r 4
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(45)
and choose α13 300 en the equilibrium point(1113957u 1113957v 1113957w) (0453 0302 0184) ag 075lt 1 s
3gtf 1195 and c3 minus 0663lt 0 erefore 1113957u isunstable thanks to Corollary 1 (5)
(3) Let αij 01 i j 1 2 3 a 28 b 1 g 3 s
3 e 3 r 45 d1 3 andd2 3 and choosed3 200 en the equilibrium point (1113957u 1113957v 1113957w)
(07 0189 02) ag 84gt 1 and c3 minus 1643lt 0us 1113957u is unstable due to Corollary 1 (6)
3 The Uniform Boundedness and the GlobalExistence of Solutions for (6)
In this section the uniform boundedness and the globalexistence of solutions for (6) are investigated when the spacedimension is one For simplicity let Ω (0 1) denote| middot |kp middot Wk
p(01) | middot |p middot Lp(01) andQT Ω times (0 T)From the consequence of a series of important papers[24ndash26] by Amann we have if u0 v0 w0 isinW1
p(Ω) withpgt 1 then (6) has a unique nonnegative solutionu v w isin C([0 T) W1
p(Ω))capCinfin((0 T) Cinfin(Ω)) whereTle +infin is the maximal existence time for the local solutionIf the solution (u v w) satisfies the estimates
sup u(middot t)w1p(Ω) v(middot t)w1
p(Ω) w(middot t)w1p(Ω) 0lt tltT1113882 1113883ltinfin
(46)
then T +infin Moreover if u0 v0 w0 isinW2p(0 1) then
u v w isin C([0infin) W2p(0 1))
In order to establish the timing uniform W12minus estimate of
the solution for system (6) the following corollaries to theGagliardondashNirenberg-type inequality play important roles
Lemma 2 -ere exists a universal constant C such that
|u|2 leC ux
11138681113868111386811138681113868111386811138681113868132 |u|
231 + |u|11113874 1113875 forallu isinW
12(0 1) (47)
|u|4 leC ux
11138681113868111386811138681113868111386811138681113868122 |u|
121 + |u|11113874 1113875 forallu isinW
12(0 1) (48)
|u|52 leC ux
11138681113868111386811138681113868111386811138681113868252 |u|
351 + |u|11113874 1113875 forallu isinW
12(0 1) (49)
ux
111386811138681113868111386811138681113868111386811138682leC uxx
11138681113868111386811138681113868111386811138681113868352 |u|
251 + |u|11113874 1113875 forallu isinW
22(0 1) (50)
Theorem 5 Let u0 v0 w0 isinW22(0 1) and (u v w) be the
unique nonnegative solution for (6) in the maximal existenceinterval [0 T) Assume that
(H1) ablt 1 bltg
(H2)8α11α21α31 gt α21α213 + α212α318α12α22α32 gt α32α221 + α223α128α13α23α33 gt α23α231 + α232α13
en there exist t0 gt 0 and positive constants M Mprimewhich depend only on di αij(i j 1 2 3) a b g s r e suchthat
sup |u(middot t)|12 |(v(middot t))|12 |w(middot t)|12 t isin t0 T( 11138571113966 1113967leMprime
(51)
max u(x t) v(x t) w(x t) (x t) isin [0 1] times t0 T1113858 11138591113864 1113865leM
(52)
and T infin Moreover if di ge 1(i 1 2 3) andd2d1 d3d1 isin [ d d] where d and d are positive constantsthen Mprime andM depend on d andd but do not ond1 d2 andd3
Complexity 9
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
In this section we always denote that C is Sobolevembedding constant or other kind of universal constantAj Bj andCj are some positive constants which dependonly on αij(i j 1 2 3) a b g s r e and Kj are positiveconstants depending on di and αij(i j 1 2 3)
a b g s r e When d1 d2 d3 ge 1 d1d2 d3d2 isin [d d] Kj
depend on d andd but do not on d1 d2 and d3
Proof By the maximum principle one can obtain that thesolutions of (6) with nonnegative initial values are alwaysnonnegative We will give the W1
2-estimates of the solution(u v w) for (6) next
Firstly we establish L1-estimates of the solution (u v w)
for (6) Taking integrations of the first three equations in (6)over the domain [0 1] respectively and then combining thethree integration equalities linearly we have
ddt
11139461
0u + ρv +
1e
w1113874 1113875dxleC1 minus l 11139461
0u + ρv +
1e
w1113874 1113875dx
(53)
where C1 (s2er)|Ω| ρ (12)(max a 1g1113864 1113865 + (1b)) andl min 1 minus ρb ((ρg minus 1)ρ) s1113864 1113865 It follows from (H1) thatthere exists a positive constant τ0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0 tgt τ0 (54)
where M0 (C1l)max 1 (1ρ) e1113864 1113865 Moreover there exists apositive constant M0prime which depends on a b g s r e and theL1minus norm of u0 v0 and w0 such that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0prime tge 0 (55)
Secondly we will obtain L2-estimates of (u v w) Wemultiply the first three equations in (6) by u v andw re-spectively and integrate over [0 1] to have
12ddt
11139461
0u2dxle minus d1 1113946
1
0u2xdx minus 1113946
1
0p11u
2xdx minus 1113946
1
0p12uxvxdx minus 1113946
1
0p13uxwxdx + 1113946
1
0uv + au
2v + u
2w1113872 1113873dx
12ddt
11139461
0v2dxle minus d2 1113946
1
0v2xdx minus 1113946
1
0p22v
2xdx minus 1113946
1
0p21uxvxdx minus 1113946
1
0p23vxwxdx + b 1113946
1
0uvdx
12ddt
11139461
0w
2dxle minus d3 11139461
0w
2xdx minus 1113946
1
0p33w
2xdx minus 1113946
1
0p31uxwxdx minus 1113946
1
0p32vxwxdx + s 1113946
1
0w
2dx
(56)
where pij i j 1 2 3 are given by (35) for (u v w) Letdlowast min d1 d2 d31113864 1113865 en we obtain that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx minus 1113946
1
0q ux vx wx( 1113857dx
+(b + 1) 11139461
0uvdx + a 1113946
1
0u2vdx + s 1113946
1
0w
2dx
(57)
where
q ux vx wx( 1113857 p11u2x + p22v
2x + p33w
2x + p12 + p21( 1113857uxvx
+ p23 + p32( 1113857vxwx + p13 + p31( 1113857uxwx
(58)
is a positive semidefinite quadratic form of ux vx andwx if(H2) holds So (H2) implies that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus dlowast
11139461
0u2x + v
2x + w
2x1113872 1113873dx
+(b + 1) 11139461
0uvdx
+ a 11139461
0u2vdx + s 1113946
1
0w
2dx
(59)
10 Complexity
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
Now we proceed in the following two cases
(1) tge τ0 Notice by (48) that |u|44 leC(|ux|22|u|21+
|u|41)leCM20(|ux|22 + M2
0) en by the Younginequality
a 11139461
0u2vdxle a 1113946
1
0
u4
2εdx + a 1113946
1
0
ε2v2dx
a2CM2
02dlowast
11139461
0v2dx +
dlowast
211139461
0u2xdx +
dlowastM20
2
(60)
Substituting (60) into (59) we have12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minusdlowast
211139461
0u2x + v
2x + w
2x1113872 1113873dx
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx +dlowastM2
02
(61)
Inequality (47) implies that |u|62 leC|ux|22|u|41+
|u|61 leCM40(|ux|22 + M2
0) erefore
minus 11139461
0u2x + v
2x + w
2x1113872 1113873dxle 3M
20 minus
19CM2
011139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
(62)
which together with (59) infers that
12ddt
11139461
0u2
+ v2
+ w2
1113872 1113873dxle minus C3dlowast
11139461
0u2
+ v2
+ w2
1113872 1113873dx1113890 1113891
3
+ C2 11139461
0u2
+ v2
+ w2
1113872 1113873dx + 2dlowastM
20
(63)
is means that there exist positive constants τ1 ge τ0and M1 depending on a b g s r e di(i 1 2 3)
such that
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1 tge τ1 (64)
When dlowast ge 1 M1 is independent of dlowast since the zeropoint of the right-hand side in (63) can be estimatedby positive constants independent of dlowast
(2) tge 0 Replacing M0 with M0prime and repeating estimates(60)ndash(63) one can obtain a new inequality which issimilar to (64) e coefficients of this new inequalitydepend not only on di(i 1 2 3) a b g s r e butalso on initial functions u0 v0 w0 en there existsa positive constant M1prime depending on a b g s r e
di(i 1 2 3) and the L2-norm of u0 v0 andw0 suchthat
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1prime tge 0 (65)
Finally L2minus estimates of ux vx and wx will be obtainedWe introduce the following scaling
1113957u u
d2
1113957v v
d2
1113957w w
d2
1113957t d1t
(66)
Denoting ξ d2d1 and η d3d1 and using u v w and t
instead of 1113957u 1113957v 1113957w and1113957t respectively then system (6) reduces tout Pxx + f(u v w) 0ltxlt 1 tgt 0
vt Qxx + k(u v w) 0ltxlt 1 tgt 0
wt Rxx + h(u v w) 0lt xlt 1 tgt 0
ux(x t) vx(x t) wx(x t) 0 x 0 1 tgt 0
u(x 0) u0(x)
v(x 0) v0(x)
w(x 0) w0(x)
0ltxlt 1
⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩
(67)
where P u + α11ξu2 + α12ξuv + α13ξuw Q ξv + α21ξuv +
α22ξv2 + α23ξvw R ηw + α31ξuw + α32ξvw + α33ξw2 andf(u v w) minus dminus 1
1 u + dminus 11 v + aξuv + ξuw k(u v w) bdminus 1
1u minus gdminus 1
1 v minus ξuv h(u v w) w(sdminus 11 minus rξw minus eξu)
We still divide the subsequent discuss into two cases
(1) tge τlowast1( d1τ1) (namely tge τ1 in the original scale) Itis clear that
11139461
0udx 1113946
1
0vdx 1113946
1
0wdxleM0d
minus 12
11139461
0u2dx 1113946
1
0v2dx 1113946
1
0w
2dxleM1dminus 22
|P|1 |Q|1 |R|1 leDK1dminus 12
(68)
Multiplying the first three equations in (67) byPt Qt andRt and integrating them over the domain[0 1] respectively then adding up the three inte-gration equalities we have12yprime(t) minus 1113946
1
0u2tdx minus ξ1113946
1
0v2tdx
minus η11139461
0w
2tdx minus ξ1113946
1
0q utvtwt( 1113857dx
+ 11139461
01+ p11ξ( 1113857utf + p12ξvtf + p13ξwtf1113858 1113859dx
+ ξ11139461
0p21utk + 1+ p22( 1113857vtk + p23wtk1113858 1113859dx
+ 11139461
0p31ξuth + p32ξvth + η+ p33ξ( 1113857wth1113858 1113859dx
(69)
Complexity 11
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
where y 111393810(P2
x + Q2x + R2
x)dx q is given by (58) Itis not hard to verify by (H2) that there exists apositive constant C4 depending only on αij(i j
1 2 3) such that
q ut vt wt( 1113857geC4(u + v + w) u2t + v
2t + w
2t1113872 1113873 (70)
erefore
12yprime(t)le minus 1113946
1
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdx minus C4ξ 1113946
1
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx
+ 11139461
01 + p11ξ( 1113857utfdx + 1113946
1
0ξ 1 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ 11139461
0p12ξvtfdx + 1113946
1
0p13ξwtfdx + 1113946
1
0p21ξutkdx
+ 11139461
0p23ξwtkdx + 1113946
1
0p31ξuthdx + 1113946
1
0p32ξvthdx
(71)
By the Hӧlder inequality one can obtain the fol-lowing estimates
11139461
0u4dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
23
11139461
0u2v2dxleM
131 d
minus (23)1 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
11139461
0u3dxleM
231 d
minus (43)1 1113946
1
0u5dx1113888 1113889
13
11139461
0uv
2dxleM231 d
minus (43)1 1113946
1
0v5dx1113888 1113889
13
11139461
0u3wdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
12
11139461
0w
5dx1113888 1113889
16
11139461
0uvwdxleM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
11139461
0u2vwdxleM
131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
(72)
Applying the Young inequality the Hӧlder in-equality the GagliardondashNirenberg inequality and
estimate (68) one can obtain the following estimatesfor the terms on the right-hand side of (71)
12 Complexity
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
minus 11139461
0u2tdxle minus
12
11139461
0P2xxdx + 1113946
1
0f2dx
minus ξ 11139461
0v2tdxle minus
ξ2
11139461
0Q
2xxdx + ξ 1113946
1
0k2dx
minus η11139461
0w
2tdxle minus
η2
11139461
0R2xxdx + η1113946
1
0h2dx
11139461
0f2dxle 2M1d
minus 21 d
minus 22 + a
2ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2M131 d
minus (23)2 1113946
1
0u5dx1113888 1113889
13
11139461
0w
5dx1113888 1113889
13
+ 2aξdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
+ 2ξdminus 11 d
minus (23)2 M
231 1113946
1
0u5dx1113888 1113889
16
11139461
0v5dx1113888 1113889
16
+ 2aξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
16
ξ 11139461
0k2dxle ξd
minus 21 d
minus 22 M1 b
2+ g
21113872 1113873 + ξ3dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
13
11139461
0v5dx1113888 1113889
13
+ ξ2gdminus 11 d
minus (43)2 M
231 1113946
1
0v5dx1113888 1113889
13
η11139461
0h2dxle ηs
2d
minus 21 d
minus 22 M1 + ηd
2ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
13
ηr2ξ2dminus (23)
2 M131
+ ηr2ξ2dminus (23)
2 M131 1113946
1
0u5dx1113888 1113889
23
+ η dr ξ2dminus (23)2 M
131 1113946
1
0u5dx1113888 1113889
16
11139461
0w
5dx1113888 1113889
12
(73)
us
minus 11139461
0u2tdx minus ξ 1113946
1
0v2tdx minus η1113946
1
0w
2tdxle minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx + C5(1 + ξ + η)d
minus 21 d
minus 22 M1
+ C6dminus (43)2 M
231 ξ(1 + η) 1113946
1
0u5
+ v5
1113872 1113873dx1113888 1113889
13
+ C7dminus (23)2 M
131 ξ2(1 + η) 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113888 1113889
23
(74)
Complexity 13
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
11139461
0utfdxle d
minus 11 1113946
1
0uutdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ d
minus 11 1113946
1
0utvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ aξ 1113946
1
0uutvdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868+ ξ 1113946
1
0uutwdx
11138681113868111386811138681113868111386811138681113868
11138681113868111386811138681113868111386811138681113868
le dminus 11
12ϵ
11139461
0udx +ϵ2
11139461
0uu
2tdx1113888 1113889 + d
minus 11
12ϵ
11139461
0vdx +ϵ2
11139461
0vu
2tdx1113888 1113889
+ aξ12ϵ
11139461
0uv
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889 + ξ
12ϵ
11139461
0uw
2dx +ϵ2
11139461
0uu
2tdx1113888 1113889
ledminus 11 dminus 1
2ϵ
M0 +a
2ϵM
231 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+ξ2ϵ
M231 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+ϵdminus 1
12
11139461
0vu
2tdx +ϵ2
dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α11ξ 11139461
0uutfdxle
α11ϵ
M231 d
minus 11 d
232 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦ +
3α11(a + 1)
5ϵξ2 1113946
1
0u5dx
+2α11a5ϵ
ξ2 11139461
0v5dx +
2α115ϵ
ξ2 11139461
0w
5dx + α11ξϵ 2dminus 11 + aξ + ξ1113872 1113873 1113946
1
0uu
2tdx
2α12ξ 11139461
0vutfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0v5dx1113888 1113889
13
+α12(a + 1)
5ϵξ2 1113946
1
0u5dx +
2α125ϵ
ξ2 11139461
0w
5dx +α12(3a + 4)
10ϵξ2 1113946
1
0v5dx
α13ξ 11139461
0wutfdxle
α13ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α13(a +(12))
5ϵξ2 1113946
1
0u5dx +
2aα135ϵ
ξ2 11139461
0v5dx
+2α13(a + 1)
5ϵξ2 1113946
1
0w
5dx +α13dminus 1
12ϵξ 1113946
1
0vu
2tdx +ϵ2
α13ξdminus 11 + α13ξ
2+ 11113872 1113873 1113946
1
0uu
2tdx
ξ 11139461
0vtkdxle
b + g
2ϵM0d
minus 11 d
minus 12 ξ +
ξ2
2ϵM
231 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+bdminus 1
12ϵξ 1113946
1
0uv
2tdx +ϵ2ξ gd
minus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
α21ξ 11139461
0uvtkdxle
α21(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+2α215ϵ
ξ2 11139461
0u5dx
+α2110ϵ
ξ2 11139461
0v5dx +
α21bdminus 11
2ϵξ 1113946
1
0uv
2tdx +
α21ϵξ2
gdminus 11 + ξ1113872 1113873 1113946
1
0vv
2tdx
2α22ξ 11139461
0vvtk dx le
α22(b + g)
ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α225ϵ
ξ2 11139461
0u5dx
+4α225ϵ
ξ2 11139461
0v5dx + α22(b + g)d
minus 11 ϵξ 1113946
1
0vv
2tdx + α22ϵξ
211139461
0uv
2tdx
α23ξ 11139461
0wvtkdxle
α23(b + g)
2ϵM
231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
minus (43)
+α23ϵξ2
bdminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx
+α235ϵ
ξ2 11139461
0u5dx + 21113946
1
0v5dx + 21113946
1
0w
5dx1113888 1113889 +α23gdminus 1
12ϵξ 1113946
1
0vv
2tdx
η11139461
0wthdxle
s
ϵd
minus 11 d
minus 12 M0 +
r
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13
+e
2ϵM
231 d
minus (43)2 ηξ 1113946
1
0w
5dx1113888 1113889
13ηϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α31ξ 11139461
0uwthdxle
α31s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0u5dx1113888 1113889
13
+α31(r + 2e)
5ϵξ2 1113946
1
0u5dx1113888 1113889
13
+α31(3r + e)
10ϵξ2 1113946
1
0w
5dx1113888 1113889
13
+α31ξϵ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
14 Complexity
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
α32ξ 11139461
0vwthdxle
α32s2ϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0v5dx1113888 1113889
13
+2α32e5ϵ
ξ2 11139461
0u5dx +
α32(r + 2e)
5ϵξ2 1113946
1
0v5dx
+α32(e +(3r2))
5ϵξ2 1113946
1
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
2α33ξ 11139461
0wwthdxle
α33sϵ
M231 d
minus 11 d
minus (43)2 ξ 1113946
1
0w
5dx1113888 1113889
13
+2α33e5ϵ
ξ2
+α33(5r + 3e)
5ϵξ2 1113946
1
0w
5dx + α33ϵξ sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0ww
2tdx
α12ξ 11139461
0uvtfdxle
α12ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+α125ϵ
2a +32
1113874 1113875ξ2 11139461
0u5dx
+aα1210ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx +α12ϵξ2
dminus 11 + ξ1113872 1113873 1113946
1
0uv
2tdx +
α12ϵξ2
dminus 11 + aξ1113872 1113873 1113946
1
0vv
2tdx
α12ξ 11139461
0uwtfdxle
α12ξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0u5dx1113888 1113889
13
+ 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+3α12(a + 1)
10ϵξ2 1113946
1
0u5dx +
aα125ϵ
ξ2 11139461
0v5dx +
α125ϵ
ξ2 11139461
0w
5dx + α12ξϵ dminus 11 +
aξ2
+ξ2
1113888 1113889 11139461
0uw
2tdx
α21ξ 11139461
0vutkdxle
α21ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α215ϵ
ξ2 11139461
0u5dx +
3α2110ϵ
ξ2 11139461
0v5dx +
α21ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vu
2tdx
α23ξ 11139461
0vwtkdxle
α23ξ2ϵ
M231 d
minus 11 d
minus (43)2 b 1113946
1
0u5dx1113888 1113889
13
+ g 11139461
0v5dx1113888 1113889
13⎡⎣ ⎤⎦
+α235ϵ
ξ2 11139461
0u5dx +
3α2310ϵ
ξ2 11139461
0v5dx +
α23ϵξ2
bdminus 11 + gd
minus 11 + ξ1113872 1113873 1113946
1
0vw
2tdx
α31ξ 11139461
0wuthdxle
α31sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α31e5ϵ
ξ2 11139461
0u5dx
+α31ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α31ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wu
2tdx
α32ξ 11139461
0wvthdxle
α32sξ2ϵ
M231 d
minus 11 d
minus (43)2 1113946
1
0w
5dx1113888 1113889
13
+α32e5ϵ
ξ2 11139461
0u5dx
+α32ξ
2
2ϵr +
35
e1113874 1113875 11139461
0w
5dx +α32ϵξ2
sdminus 11 + rξ + eξ1113872 1113873 1113946
1
0wv
2tdx
(75)
Complexity 15
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
erefore
11139461
01 + p11ξ( 1113857utfdx + ξ 1113946
1
01 + p22( 1113857vtkdx + 1113946
1
0η + p33ξ( 1113857wthdx
+ ξ 11139461
0p12vtfdx + ξ 1113946
1
0p13wtfdx + ξ 1113946
1
0p21utkdx
+ ξ 11139461
0p23wtkdx + ξ 1113946
1
0p31uthdx + ξ 1113946
1
0p32vthdx
le λϵξ 11139461
0(u + v + w) u
2t + v
2t + w
2t1113872 1113873dx +
C8
ϵM0d
minus 11 d
minus 22 (1 + ξ + η)
+C9
ϵM
231 d
minus (43)2 ξ 1 + d
minus 11 + ξ + η1113872 1113873 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx1113890 1113891
13
+C10
ϵξ2 1113946
1
0u5
+ v5
+ w5
1113872 1113873dx
(76)
where λ is a positive constant Choose a small enoughpositive number ε ε(di αij i j 1 2 3 a b g s
r e) such that λεltC4 Combining (74) and (76) onecan obtain12yprime(t)le minus
12
11139461
0P2xxdx minus
ξ2
11139461
0Q
2xxdx minus
η2
11139461
0R2xxdx
+ B1K2dminus 11 d
minus 12 + B2K3d
minus (43)1 z
13
+ B3K4dminus (23)1 z
23+ B4K5z
(77)
where z 111393810(u5 + v5 + w5)dx K2 (1 + ξ + η)
(M0 + M1dminus 11 dminus 1
2 ) K3 M231 ξ(1 + dminus 1
1 + ξ + η)
K4 M121 ξ2(1 + η) andK5 ξ2 Clearly Pge α11
ξu2 Qge α22ξv2 andRge α33ξw2 It follows from (49)that |P|5252 leC(|Px|2|P|321 + |P|521 ) and
zleB5ξminus (52)
11139461
0P52
+ Q52
+ R52
1113872 1113873dx
leB6ξminus (52)
K321 d
minus (32)1 y
12+ B6ξ
minus (52)K
521 d
minus (52)1
z13 leB7ξ
minus (56)K
121 d
minus (12)1 y
16+ B7ξ
minus (56)K
561 d
minus (56)1
z23 leB8ξ
minus (53)K1d
minus 11 y
13+ B8ξ
minus (53)K
531 d
minus (53)1
(78)
Moreover it follows by (50) that |Px|1032 leC(|Pxx|22|P|431 + |P|1031 )leB9K
431 d
minus (43)1 (|Pxx|22 + K2
1dminus 21 ) So
minusξ2
1113946
1
0
P2xxdx minus
12
1113946
1
0
Q2xxdx minus
η2
1113946
1
0
R2xxdx
le minus B10 min 1 ξ η1113864 1113865Kminus (43)1 d
431 y
53+(1 + ξ + η)K
21d
minus 21
(79)
Substituting the above inequality into (80) and thenmultiplying it by d2
2 we have
12
yprime(t)le minus A1 min 1 ξ η1113864 1113865Kminus (43)1 d
432 y
53
+ A2ξminus (56)
K121 K3d
minus (16)2 y
16
+ A3ξminus (53)
K1K4dminus (13)2 y
13
+ A4ξminus (52)
K321 K5d
minus (12)2 y
12
+ A5 K21(1 + ξ + η) + K2ξ1113960
+ K561 K3ξ
minus (56)d
minus (16)2 + K
531 K4ξ
minus (53)d
minus (12)2
+ K521 K5ξ
minus (52)d
minus (12)2 1113961
(80)
where y 111393810[(d2Px)2 + (d2Qx)2 + (d2Rx)2]dx
Iinequality (77) implies that there exist 1113957τ2 gt 0 and apositive constant 1113958M2 depending only ona b g s r e d1 d2 d3 αij(i j 1 2 3) such that
11139461
0d2Px( 1113857
2dx 11139461
0d2Qx( 1113857
2dx 11139461
0d2Rx( 1113857
2dxle 1113958M2 tge 1113957τ2
(81)
In the case that d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]the coefficients of inequality (83) can be estimated bysome constants depending on d and d but doing noton d1 d2 andd3 So 1113958M2 depends on αij(i j
1 2 3) a b g r s e d d and is irrelevant to d1
d2 andd3 when d1 d2 d3 ge 1 d2d1 d3d1 isin [d d]Since
16 Complexity
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
ux
vx
wx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠ J
minus 1
Px
Qx
Rx
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
J
Pu Pv Pw
Qu Qv Qw
Ru Rv Rw
⎛⎜⎜⎜⎜⎜⎜⎜⎜⎜⎝⎞⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠
(82)
by detJgt ξη we have
d2ux
11138681113868111386811138681113868111386811138681113868 + d2vx
11138681113868111386811138681113868111386811138681113868 + d2wx
11138681113868111386811138681113868111386811138681113868leL d2Px
11138681113868111386811138681113868111386811138681113868 + d2Qx
11138681113868111386811138681113868111386811138681113868 + d2Rx
111386811138681113868111386811138681113868111386811138681113872 1113873
0lt xlt 1 tgt 0
(83)
where L is a constant depending only onξ η αij(i j 1 2 3) After scaling back and con-tacting estimates (84) and (85) there exist positiveconstants τ2 and M2 depending on αij(i j
1 2 3) di(i 1 2 3) a b g r s e such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2 tge τ2 (84)
When d1 d2 d3 ge 1 d2d1 d3d1 isin [d d] M2 de-pends on d andd but do not on d1 d2 d3 ge 1
(2) tge 0 Modifying the dependency of the coefficients ininequalities (68)ndash(84) namely replacing M0 andM1with M0prime andM1prime there exists a positive constant M2primedepending on αij(i j 1 2 3) di(i 1 2 3) a b
g r s e and the W12minus norm of u0 v0 w0 such that
11139461
0u2xdx 1113946
1
0v2xdx 1113946
1
0w
2xdxleM2prime tge 0 (85)
Furthermore when di ge 1(i 1 2 3) ξ η isin [ d d] M2primedepends on d andd but do not on di(i 1 2 3)
Summarizing estimates (54) (64) and (84) and theSobolev embedding theorem there exist positive constantsM andMprime depending only on αij(i j 1 2 3) di
(i 1 2 3) a b g r s e such that (51) and (54) hold Inparticular M andMprime depend only on αij(i j 1 2 3)
a b g r s e d d but do not on di(i 1 2 3) whendi ge 1(i 1 2 3) ξ η isin [ d d]
Similarly there exists a positive constant Mprimeprime dependingon αij(i j 1 2 3) di(i 1 2 3) a b g r s e and the ini-tial functions u0 v0 andw0 such that
|u(middot t)|12 |v(middot t)|12 |w(middot t)|12 leMprimeprime tge 0 (86)
Furthermore in the case that di ge 1(i 1 2 3)
ξ η isin [ d d] Mprimeprime depends only on d andd but do not ondi(i 1 2 3) us T +infin is completes the proof ofeorem 5
4 Asymptotic Behavior
In this section we will discuss the global asymptotic behaviorof the positive equilibrium point 1113957u for (6)
Theorem 6 Assume that all conditions in -eorem 5 aresatisfied Furthermore if aglt 1 and
4λρ1113957u1113957v1113957wd1d2d3 gt 1113957uM2 λα231113957v + ρα32 1113957w( 1113857
2d1 + 2α11M + α12M + α13M( 1113857
+ λ1113957vM2 α131113957u + ρα31 1113957w( 1113857
2d2 + α21M + 2α22M + α23M( 1113857
+ ρ1113957wM2 α121113957u + λα211113957v( 1113857
2d3 + α31M + α32M + 2α33M( 1113857
(87)
where λ ((2 minus ag)1113957u + g)g2 ρ 1e M is given by (58)then the positive equilibrium point 1113957u (1113957u 1113957v 1113957w) for (6) isglobally asymptotically stable
Proof Let (u v w) be a solution of (6) with u0 v0 w0 ge( equiv )0 From the strong maximum principle for parabolicequations we can prove that u v wgt 0 for any tgt 0
Define
V(u v w) 11139461
0u minus 1113957u minus 1113957u ln
u
1113957u1113874 1113875 + λ v minus 1113957v minus 1113957v ln
v
1113957v1113874 11138751113882
+ ρ w minus 1113957w minus 1113957w lnw
1113957w1113874 11138751113883dx
(88)
where λ ((2 minus ag)1113957u + g)g2 and ρ 1e ObviouslyV(u v w) is nonnegative and V(u v w) 0 if and only ifu 1113957u v 1113957v andw 1113957we time derivative ofV(u v w) forsystem (6) satisfies that
dV(u v w)
dt minus 1113946
1
0
1113957u
u2 d1 + p11( 1113857u2x +
λ1113957v
v2d2 + p22( 1113857v
2x1113896
+ρ1113957w
w2 d3 + p33( 1113857w2x +
α121113957u
u+λα211113957v
v1113888 1113889uxvx
+α131113957u
u+ρα31 1113957w
w1113874 1113875uxwx
+λα231113957v
v+ρα32 1113957w
w1113888 1113889vxwx1113897dx
minus 11139461
0
v
1113957uu(u minus 1113957u)
2+
bλu
1113957vv(v minus 1113957v)
21113896
+ ρr(w minus 1113957w)2
minusgλ + 1
1113957u+ a1113888 1113889(u minus 1113957u)(v minus 1113957v)
+(1 minus ρe)(u minus 1113957u)(w minus 1113957w)1113865dx
(89)
Complexity 17
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
It is easy to know that the second integrand in the aboveequality is positive definite by the choices of λ and ρ and thefirst integrand in the above equality is positive semidefinite if
4λρ1113957u1113957v1113957w d1 + p11( 1113857 d2 + p22( 1113857 d3 + p33( 1113857
+ α121113957uv + λα211113957vu( 1113857 α131113957uw + ρα31 1113957wu( 1113857 λα231113957vw + ρα32 1113957wv( 1113857
gt ρ1113957w α121113957uv + λα211113957vu( 11138572
d3 + p33( 1113857
+ λ1113957v α131113957uw + ρα31 1113957wu( 11138572
d2 + p22( 1113857
+ 1113957u λα231113957vw + ρα32 1113957wv( 11138572
d1 + p11( 1113857
(90)
By the maximum-norm estimate in eorem 5 condi-tion (87) implies that (90) holds erefore if the all con-ditions in eorem 6 hold there exists a positive constant δsuch thatdH(u v w)
dtle minus δ1113946
1
0(u minus 1113957u)
2+(v minus 1113957v)
2+(w minus 1113957w)
21113960 1113961dx
dH(u v w)
dtlt 0 (u v w)neE3
(91)
Using integration by parts the Holder inequality and(52) one can easily verify that ddt 1113938
10[(u minus 1113957u)2 + (v minus 1113957v)2 +
(w minus 1113957w)2]dx is bounded from above en from Lemma 1and (91) we have
|u(middot t) minus 1113957u|2⟶ 0
|v(middot t) minus 1113957v|2⟶ 0
|w(middot t) minus 1113957w|2⟶ 0
t⟶infin
(92)
It follows from the GagliardondashNirenberg inequality|u(middot t)|infin leC|u|1212 |u|122 that
|u(middot t) minus 1113957u|infin⟶ 0
|v(middot t) minus 1113957v|infin⟶ 0
|w(middot t) minus 1113957w|infin⟶ 0
t⟶infin
(93)
Namely (u v w) converges uniformly to (1113957u 1113957v 1113957w) Bythe fact that V(u v w) is decreasing for tge 0 it is obviousthat (1113957u 1113957v 1113957w) is globally asymptotically stable So the proofof eorem 6 is completed
Example 2 e following parameters satisfy all the con-ditions of eorem 6
α11 2
α12 1
α13 10
α21 32
α22 12
α23 1
α31 10
α32 2
α33 3
a 12
b 12
g 1
s 3
e 1
r 5
d1 d2 d3≫ 1
(94)
Remark 3 In model (6) if coefficients of reaction functionssatisfy the conditions of eorem 6 the diffusion matrix ispositive definite and the self-diffusion coefficients are largeenough then the model has no nonconstant positive steadystate
Data Availability
Data sharing is not applicable to this article as no datasetswere generated or analysed during the current study
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this paper
18 Complexity
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19
Acknowledgments
is research was supported by the National Natural ScienceFoundation of China (nos 11761063 and 11661051)
References
[1] K G Magnusson ldquoDestabilizing effect of cannibalism on astructured predator-prey systemrdquo Mathematical Biosciencesvol 155 no 1 pp 61ndash75 1999
[2] F van den Bosch A M de Roos and W Gabriel ldquoCanni-balism as a life boat mechanismrdquo Journal of MathematicalBiology vol 26 no 6 pp 619ndash633 1988
[3] M E Gurtin and D S Levine ldquoOn populations that can-nibalize their Youngrdquo SIAM Journal on Applied Mathematicsvol 42 no 1 pp 94ndash108 1982
[4] O Diekmann R M Nisbet W S C Gurney andF van den Bosch ldquoSimple mathematical models for canni-balism a critique and a new approachrdquo Mathematical Bio-sciences vol 78 no 1 pp 21ndash46 1986
[5] A Hastings ldquoCycles in cannibalistic egg-larval interactionsrdquoJournal of Mathematical Biology vol 24 no 6 pp 651ndash6661987
[6] C Kohlmeier and W Ebenhoh ldquoe stabilizing role ofcannibalism in a predator-prey systemrdquo Bulletin of Mathe-matical Biology vol 57 no 3 pp 401ndash411 1995
[7] F van den Bosch and W Gabriel ldquoCannibalism in an age-structured predator-prey systemrdquo Bulletin of MathematicalBiology vol 59 no 3 pp 551ndash567 1997
[8] J D Murray Mathematical Biology I An IntroductionSpringer New York NY USA 3rd edition 2003
[9] N Shigesada K Kawasaki and E Teramoto ldquoSpatial seg-regation of interacting speciesrdquo Journal of -eoretical Biologyvol 79 no 1 pp 83ndash99 1979
[10] S-A Shim ldquoUniform boundedness and convergence of so-lutions to the systems with cross-diffusions dominated by self-diffusionsrdquo Nonlinear Analysis Real World Applicationsvol 4 no 1 pp 65ndash86 2003
[11] Y S Choi R Lui and Y Yamada ldquoExistence of global so-lutions for the Shigesada-Kawasaki-Teramoto model withstrongly coupled cross-diffusionrdquo Discrete amp ContinuousDynamical Systems-A vol 10 no 3 pp 719ndash730 2004
[12] P Y H Pang and M Wang ldquoStrategy and stationary patternin a three-species predator-prey modelrdquo Journal of Differ-ential Equations vol 200 no 2 pp 245ndash273 2004
[13] S M Fu Z J Wen and S B Cui ldquoOn global solutions for thethree-species food-chain model with cross-diffusionrdquo ActaMathematica Sinica-A vol 50 pp 75ndash88 2007
[14] S M Fu and X L Yang ldquoNonconstant positive steady statesof a predator-prey model with cannibalismrdquo InternationalJournal of Information and Systems Sciences vol 8 pp 250ndash260 2012
[15] S Fu L Zhang and P Hu ldquoGlobal behavior of solutions in aLotka-Volterra predator-prey model with prey-stage struc-turerdquo Nonlinear Analysis Real World Applications vol 14no 5 pp 2027ndash2045 2013
[16] L Zhang and S Fu ldquoGlobal bifurcation for a Holling-Tannerpredator-prey model with prey-taxisrdquo Nonlinear AnalysisReal World Applications vol 47 pp 460ndash472 2019
[17] B Dubey B Das and J Hussain ldquoA predator-prey interactionmodel with self and cross-diffusionrdquo Ecological Modellingvol 141 no 1ndash3 pp 67ndash76 2001
[18] F Zhang Y Chen and J Li ldquoDynamical analysis of a stage-structured predator-prey model with cannibalismrdquo Mathe-matical Biosciences vol 307 pp 33ndash41 2019
[19] B Buonomo and D Lacitignola ldquoOn the stabilizing effect ofcannibalism in stage structured population modelsrdquo Math-ematical Biosciences and Engineering vol 3 pp 717ndash7312006
[20] K J Brown P C Dunne and R A Gardner ldquoA semilinearparabolic system arising in the theory of superconductivityrdquoJournal of Differential Equations vol 40 no 2 pp 232ndash2521981
[21] G Simonett ldquoCenter manifolds for quasilinear reaction-diffusion systemsrdquo Differential and Integral Equations vol 8pp 753ndash796 1995
[22] A-K Drangeid ldquoe principle of linearized stability forquasilinear parabolic evolution equationsrdquo Nonlinear Anal-ysis -eory Methods amp Applications vol 13 no 9pp 1091ndash1113 1989
[23] P Liu J Shi and Z-A Wang ldquoPattern formation of theattraction-repulsion Keller-Segel systemrdquo Discrete amp Con-tinuous Dynamical Systems-B vol 18 no 10 pp 2597ndash26252013
[24] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-I Abstract evolution equationsrdquo Nonlinear Analysis-eory Methods amp Applications vol 12 no 9 pp 895ndash9191988
[25] H Amann ldquoDynamic theory of quasilinear parabolic equa-tions-II Reaction-diffusionrdquo Differential and Integral Equa-tions vol 3 pp 13ndash75 1990
[26] H Amann ldquoDynamic theory of quasilinear parabolic sys-temsrdquoMathematische Zeitschrift vol 202 no 2 pp 219ndash2501989
Complexity 19