thoery of matrices mac duffee
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The theory of matrices / by C.C. MacDuffee.
MacDuffee, Cyrus Colton, 1895-
New York : Chelsea , 1956.
http://hdl.handle.net/2027/mdp.49015001327999
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.
X ,
A
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E D R MA TH E MA T K
G E N Z G B I E T
B E N V O N D R C H R I FT E I TUN G
L B L A TT F R MA T H E MA T K "
N D
irst dit ion
UB L I S H I N G C O MPA N Y
E W O R K
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HE U N I T D TA T S O F A M R I C A
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maticalabstractionunderlyingmany
s.Thusbilinearand uadraticforms,linear
rcomple systems),linearhomogeneoustrans-
orfunctionsarevariousmanifestationsof
anchesofmathematicsasnumbertheory,
uations,continuedfractions,pro ective
eofcerta inportionsof thissub ect. ndeed,
propertiesofmatriceswerefirstdiscovered
ularapplication,andnotuntilmuchlater re-
y.
hinthescopeof thisboo togiveacompletely
theory,noris itintendedtoma eitan
esub ect. thasbeenthedesireof thew riter
rectionsinwhichthetheoryleads sothatthe
aysee itse tent. Whilesomeattempthas
parts ofthetheory,ingeneralthe material
sfoundintheliterature,the topicsdiscussed
hiche tensiveresearchhasta enplace.
heoremsa briefandelegantproofhas
tishopedthat mostofthesehavebeen
andthatthe readerwillderiveasmuchplea-
did thewriter.
ueDr. aurens arleB ushforacrit ical
ee.
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dDeterminants1
deredsets1
rices5
cands ew matrices5
nts8
0
nors12
antsofhigherdimension15
utativesystems1
ce uation17
tion17
uation17
inimume uation20
ts22
4
acterist icroots25
ofunitarymatrices28
n t eg r al M a tr i c es 2 9
sina principalidealring29
odularmatrices31
s31
sors35
37
4 0
r ic e s 40
delementarydivisors43
ri 44
5
fmatrices48
ormations50
sina principalidealring51
ntegralelements54
sina field5
aca lly closedf ie ld 0
es 2
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8
tsinaf ield 9
stic73
le uivalence75
and orthogonalmatrices78
n of m at r ic e s 81
product81
power-matrices85
u at io ns 8 9
uation89
9 4
tion95
ces97
s97
9
ntsarefunctionsofcomple variables..101
alsofmatrices102
er 104
ts104
0
finiteorder 10
s108
numerablenumberofrowsandcolums. 110
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dDeterminants.
neara lgebra2tofordernoveraf ie ld% is
numbers , / , y , . . . andthreeoperations,
t ion( )andsca larmultiplicationsuchthat
, a a r e un i u e ly d e fi n ed n u mb e rs o f 2 1, w h er e a i s
hat additioniscommutativeandasso-
tionisdistributivewithrespect toaddi-
it isassumedthat
( ab ) , a ) H b p) = (a b o rf ) ,
+ b
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ndDeterminants.
braisassociative,then
) e = e, (e e ) .( ' , , i, 2 , )
mbersci)iaresub ecttothen conditions
. = Z k C i k c , r. ( , /, f, s = l, 2n )
eredsetofnumbers
alarmultiplicationof suchsetsaredefinedby
, r ) = (Z k c t r C , s ) ,
k R k .
eundermultiplicationinthe samemanner
1. f thesetsR tarenotlinearly independent
t obtainedbyborderingR tabovewitha
e le ftw ithdri( ronec er s8), are linearly inde-
icwiththeei undermultiplication2.
sis definedbytheidentity
c ) ,
sgivearepresentationofthe algebra3.
hesameyearthatPo incare snotew as
ote: ThePeirces(subse uently to1858)
alizationofH amilton stheory,andhad
ffect thatprobablyallsystemsofalgebraical
ssociativelawof multiplicationwouldbeeven-
withlineartransformationsofschemata
epresentation....That suchmustbethe
sert,butit isverydifficulttoconceivehow
econsiderationsof 2suggestthat
2overgcan besodefinedthateveryalgebra
somorphicwithoneof itspropersub-algebras5.
lassevonMatrizen, p. 59. B erlin1901.
undihreZ ahlentheorie , p. 35.
. R . A c a d. c i ., P a ri s V o l . 9 9 ( 18 8 4) p p . 74 0 7 4 2.
hm .G es . W is s. P ra gu e (1 88 7) p p. 1 6 1 8 . t ud y, . :
V o l . 4 (1 9 04 ) 1 0 .
. M a th . V o l . ( 1 88 4 ) pp . 2 70 2 8 .
erneA lgebraV o l. p. 37. B erlin1930.
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dDeterminants.
hetotalmatric algebra9ftofordern2 over
ets ofn2numbereachofthe type
operationsandpostulates:
dB = (brs) aree ualifandonly ifar,= brs
sdefinedby
+ b ) .
nabeliangroup withrespecttoaddition,
hee lementsof thering9 . The identity set,
will bedenotedby0.
tionisdefinedby
mn multiplicationof thesets. Theproduct
O A = A O = 0 f o r e v er y A .
ociative,sincemultiplicationinfitis as-
Z u ( ^ ) ^
A ( B C ) .
vewithrespect toaddition,forthe
( a H + i ) cu )
A C + B C .
B ) = C A + C B .
tricalgebraoforder n2overaring 9 is
sconnectionbyspecializing9 , formulti-
allynon-commutativeevenwhen9 isacom-
erseastomultiplicationofA = | = 0doesnot
ingw ithoutdiv isorsofzero . f , how ever,
ite lement1, thenthematri = (
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dDeterminants.
d co lumns, B nhas7row sand co lumns,
sand co lumns. t isreadilyverifiedthat
r iB i s ,( r, s, = 1 , 2)
c s / 1 < ; . , Z ? i . a r e mu l ti p li e d r o w by c o lu m n .
onsofthematricesintobloc s,providedthe
dinthesamew aysastheco lumnsofA .
ray tomeananorderedsetof e lements
e ua lif andonly ifeachconsistsof thesame
correspondinge lementsaree ua l. f
be arrangedintheformof arectangle.Under
sumorproduct oftwoarraysmayhave
ntheyarematricesor asinthelast paragraph
tfrommatrices,but nosuchoperationsare
array.
ceofanarrayof 2elements, butit ismuch
emberofa totalmatricalgebraforwhich
andmultiplicationaredefined.Theimportance
sfromthe rulesofcombinationofmatrices,
ayberepresentedbys uarearraysisin-
ly remar ed: Oneof thef irsto f suche -
relyuncalledfor,especiallyin ngland,
w ordmatri )ta etheplacea lreadysatisfactorily
.H owsatisfactorythiswaswillbe readily
h te t b oo s o f d et e rm i na n ts l i e c o tt s 1 . A
dcertainlyaddfurthertohis creditifin
hemademanifestbypreceptande amplean
ngineachother scompanythetermsarray,
edona consistentterminology.Theword
sedby y lvester3todenotearectangulararray
canbeformed.Theconceptof amatri as
risduein essencetoH amiltonbutmoredirectly
amongothers, uses matri " f o rarectangular
oramemberofamatrica lgebra5. B utthees-
hateletagrees,istodifferentiatetheconcepts.
atiseonthetheoryofdeterminants. C ambridge1880.
o y . o c . . A f r ic a V o l . 1 8 I ( 1 92 9 ) pp . 2 19 - 22 7 .
. V o l . 37 ( 1 85 0 ) pp . 3 3 3 7 0 - C o l l. W o r s V o l .
ndonPhil. oc. V o l. 148(1858)pp. 17-37-C o ll. Wor s
.
upesabeliensf inis. Paris1924.
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dDeterminants.
atrices. A matri o f thetype
]
edefinitionsof additionandmultiplication
+ i h, h, . .. , ] = f t + h, 2 + l 2, .. ., n + l n ,
1, l2 ,. . ., l ] = ft l1 , 2 l2 ,. . . n ln .
o fw hosediagona le lementsaree ua lisca lled
, , ... , ] , th en k + l = k + i , k S { = k l ,
atricesofconstitutea subringofW iso-
f or * a nd A f or k A . f 9 1 is a r in g wi th
/ .
sacommutativeringwithunit element,andif
e ry X i n W l , t he n A i s s c a la r .
s
, thereresults
? drpdi, la i,, a rp8, = drpats. (r, s, p, = 1, 2, . .. , n)
p t h i s gi v es a r p = 0 , wh i le f o r = s a n d r = p
s s.
cands ew matrices. Thematri A T= ( sr)
,)bychangingrowstocolumnsis calledthe
matri suchthat T= isca lledsymmetric,
T = Q i s c a l l ed s e w 3 (s e w -s y mm e tr i c, o r
M a th . V o l . ( 1 88 4 ) pp . 2 70 - 28 - C o l l . W o r s
4.
differentnotationsforthetransposehavebeenused,
, A 1 , , A . T h e pr e se n t no t at i on i s i n e e pi n g wi t h a sy s te m at i c
mayfind favor.
e w. M at h . V o l . 32 ( 1 84 ) p p . 11 9 1 2 3 - C o l l. W o r s
3 3 . a g ue r re : . c o le p o ly t ec h n. V o l . 2 5 (1 8 7 ) p p. 2 1 5 to
vr es V o l . p p. 2 28 -2 33 .
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dDeterminants.
K ) T= A T + B T + r T.
sacommutativering(A B ... )T= T...B TA T.
i ) T = C Z & i r , i ) = B T A T . T he g e ne r al t h eo r em
ringinwhich2 = a issolvableforeverya,
er91is-uni ue lye pressibleasasumofasymmetric
, T = , Q T = -0 .
T= -Q sothat = A + A * ,Q = - .
it ispossibleto formasymmetricmatri and
heabovemanner.
R beana lgebraof - rowedmatricesw ith
sdesirableto haveassociatedwithevery
mber (A )o f% w hichw ouldservethepurposeof
dwouldbe attainedbyfindingascalar
lementsarsofageneralmatri A suchthat
) isanon-constantrationa lintegra lfunction
esuchthat
) (B ) .
( 2) b y t a i n g B = t h at ( A ) = { A ) 9 ( 1) ,
c on s ta n t, ( 1 ) = 1 . H B = 0 , (2 ) g iv e s ( 0 )
a in b e ca u se ( A ) i s n o t c on s ta n t, ( 0 ) = 0 .
i n st a nc e , le t
( t)
7 , T( 1 /< ) = / .
) ) = 1 , i t fo l lo w s th a t ( W ( t )) i s i n de p en d en t
mberof theabovee uationwouldbeof
e (W(t))hasforeveryva lueof tthesame
0, namely
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Determinants.
( V ) = i , ( T = ( T 2 ). i nc e ( T( t) ) 0( ( 1/ O )
esamedegreeX intthat0(7(1/ / )) isin1// , it
tbeamonomiala^ t7 in/ . ince (T(i))= 1,
vo etheminimumprinciple(1)andassumethat
fedbyactua llyobta iningunderthisrestrict iona
enre uirements.Then
1
l). Hence
r i , 9 ( TA ) = t d (A ) s o t ha t
sa po lynomia linthee lementsw hich
rinthe elementsofeachrow.
{ A ) , i t fo ll ow s th at
gessignw hentw orowsarepermuted.
ststatedwerecalledbyW eierstrassthe
fadeterminant. B y1 .
add, whenceby2 ,
+ eA , A i ... A J l A , fl 2A , < * n h = 0 .
/ > , & , . . .A is0if tw osubscriptscoincide, w hile if
e al l d is t in c t, i e i, i ,. .. a c co r di n g as
&
( 1 ) = i , i t f ol l ow s t ha t b 1, 2 = 1 . H e n c e
A ,A , ... A . 1 A 1 2 A ,
overa llpermutations(hl, hi, . . . , h )o f
, ^ is1or 1accordingasthepermutation
. H ense l: . re ineangew . Math. V o l. 159(1928)
r : Z u r D et e rm i na n te n th e or i e. 1 8 8 1 8 87 W e r e
2 8 . r o ne c e r : V o r le s un g en u b er d i e Th e or i e de r D et e r-
t. se . Teubner1903.
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dDeterminants.
)satisfiesthedemandsofH enselwillfollow
ptheentiretheoryofdeterminantsfromthe
fW eierstrass1.
ants. A s C ay ley remar ed, the idea
array )precedesthatofdeterminant 2. A determin-
dinaprecisewaywith anarrayofn2ordered
wseemsto havebeencleartoC auchywho
eatmentofdeterminants,atreatmentwhich
pontoday3.Unfortunatelytheword deter-
dayto meanbothanarrayanda number
y . (Notetheremar sofMuirin 3, and
fB ocher4. F oraveryclearstatementof the
oremsfromthepresentpointofview,see
br a , d e G ru y te r 1 92 . )
esenttractforan e tendedtreatment
practicallycompletebibliographyisgiven
determinantsinthehistorica lorderofdeve lop-
190 23. Theearlyhistory isattractively
er, V orlesungeniiberdieTheoriederDeter-
03 , p .1 9 . A n e c e ll e nt r e fe r en c e bo o i s
E i n fu h ru n g in d i e De t er m in a nt e nt h eo r ie , e i pz i g
arrayw ithelementsinaf ie ldgandletd(A ) or
nant. A few importanttheoremsare listedforfuture
d(A ).
btainedfromA bytheinterchangeoftworows
d ( A ) .
sortwo columnsofA areidentical,d(A )= 0.
ult,namelyinnotingthatthe hypothesis
henced(A ) = 0, fa ilsw henghasthecharacter-
odifiedtoincludethis case5ortheresult
btainedfromA bymultiplyinganyrowor
t h en d ( B ) = d ( A ) .
s uarearrayeachelementofwhose throw
, t + .. . + d s m (s = i , 2, . .. , n)
sp e c. V o l .3 7 ( 19 2 7) p p . 43 3 4 3 a n d 45 7 4 5 8.
ew . Math. V o l. 50(1855)pp. 282 285.
y techn. V o l. 10(1815)pp. 51 112.
mer. Math. MonthlyV o l. 32(1925)pp. 182 185.
e in e a ng e w. M at h . V o l . 1 7 ( 1 93 2 ) p. 1 9 7.
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dDeterminants.
2 ) + . .. + d ( A m ) ,
obta inedby replacingthee lementsof the throw
n h . i m il a rl y f or c o lu m ns .
sobtainedfromA byaddingtoanyrow(or column)
heotherrows(co lumns), thend(B ) d(A ).
ra y o f n ro w s,
ar , k \
a r,s
ar S t
norarrayofA . A rr " J isaprincipa lm inorarray.
overthe i^ j w aysofse lectingthe numbersi1, . . ., i
,.. .,nwithoutregardto order,andthesign
dingasthesubstitution
.. ., i \
.. r
a rs . e tA r s de no te d ( A \ \ \ ' . . , r, Z \ \ r , \ \ . . . ) ,
a c co r di n g as
, . . . , n
1 , . . ., n
thecofactoro farsinA .
a ip A i t= d p d ( A ) ,
e r s d e lt a .
ndB ben-rowedmatriceswithelementsina
nm-row edminormatri o f theproductA B .
erallselections ofi1,.. .,imfrom1,. ..,n
= d ( A ) d ( B ) .
d. ci. Paris1772.
bra ictheories, p. 49. C hicago192 .
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dDeterminants.
fA isanm. narrayw ithe lementsina
istheorderofaminors uarearrayofA o f
determinantisnotzero1. fA iss uareof
gisca lledthenull ityofA . 2
s uarearrayofordern, withelementsina
g = n , t h er e e i s t e a c tl y l i n e ar l y
nsamongtherows(columns)ofA ,andcon-
ofA sothatthefirst rarelinearlyindependent
mnislinearlydependentuponthese.C all
Thenev idently (A )= (B ). Thereare
n de p en d en t r el a ti o ns
+ h gh e= hh
r + 1 , . .. , n )
B y Theorems7.5and7. 4every (r- - i)-
eterminantwhichcanbe writtenasalinear
ntseachhavingatleasttwoe ualcolumns,
r.
Theorem7. 8
+ . . .+ b p e B % + b pU B f t = 0
thecofactorsB % 1are independentof , sothere
+ b p eC g h + bp hC h h = 0
erforh > , C hh4= 0sinceB iso f ran .
roflinearlyindependentlinearrelationsamong
a st n g , s o r ^ g. H e n c e g = r, n r = .
= 0 , g ( B ) + g ( C ) i n . Fo r e ve r y B t h er e
( B ) + g ( C ) = n .
u a t i on A X = 0 o f r an n g ( A ) i s c al l ed
teby( )thevectoror one-columnarray
e n (y ) = A ( ) c a n be w r it t en f o r
= 1 , 2 ,. .. , n) .
ngew . Math. V o l. 8 (1879)pp. 1 19. Theconcept
plicit , how ever, inapaperby . H eger: Den schr. A k ad.
1 85 8 ) pt . 2 p p. 1 1 2 1.
o p i n s Un i v. C i r c u l ar s V o l . l l ( 18 8 4) p p . 9 1 2
V p p. 1 3 3- 1 45 .
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dDeterminants.
lu t io n o f th e e u a ti o n A B = 0 , a nd i f ( ) i s a n
B ( )isthemostgenera lsolutionof the
ctor(z)rangesoverthesolutionsof thee uation
) r e pr e se n ts e a c tl y ( B ) (A B ) l i n e ar l y in -
n ( A B ) i n de p en d en t s ol u ti o ns o f t he e u a ti o n
e a = n ( B ) s o l ut i on s ( z ) , ( z ) , . .. , ( zM ) o f th e
f thesearee tendedby theso lutions(z( +1)), . . .. (zw )
s o lu t io n s, t h e r a = ( B ) ( A B )
1)), . . . , B (^ r))are independent. Forare lation
) + + C , B ( M) = B ( C + 1 (2 ' + 1 > )+ + C , (i ) )= 0
.. .+ C , = C 1 (/ )+ + C ( iW ),
= C T = 0.
,C arethreematricesofordern withelements
) q ( B ) + q (A B C ) .
by B C . T he n A = > ( B C ) ( A B C ) i s
), (y ), . .. f o rw hichA B C (y )= 0andthe
( y ) , .. . ar e i nd e pe n de n t. T h en ( z ) = C ( y ) ,
a ti s fy t h e e u a ti o n A B ( z ) 0 , a nd t h e ve c to r s
) , B ( z ) = C ( y ) , .. . ar e i nd e pe n de n t. B u t s i n ce t h er e
) ( A B ) s u ch v e ct o rs 1 ( /) , ( z ) , . .. ,
) .
ofthe prdductoftwomatricesisat least
therfactor,andat mostasgreatasthe sumof
1.
n iu s t h eo r em g i ve s ( A B ) ^ q ( B ) w he n
) ^ q ( B ) a nd w he n B = 7 , it g iv es
( A C ) .
w eds uarematri w ithe lementsinadomainof
ield% asasub-variety,thecolumn-nullity
f isthenumberof linearly independentlinear
nsofA withcoefficientsin^ .Thecolumn-
erow-nullity3.
eu B . A k a d . W i s s . 19 1 1 pp . 2 0 2 9 .
w of n u ll i ty . o h ns H o p i n s Un i v. C i r c u l ar s V o l . 3 ( 1 88 4 )
C o ll .W o r s V o l. V p p. 13 3 1 45 .
nn. ofMath. i lV o l. 27(1925)pp. 133 139.
mati . MacDuf fee.
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dDeterminants.
matri ofran ,andd A j ,...A is denoted
m = ( ) , t h en t h e m- r ow ed s u a re m a tr i
. 1
o lumnsofA arrangedsothat >n = j = 0. The
sare linearcombinationsof thef irst row s, so if suitable
first rowsareaddedtoeachof thelast
se lattermaybemadetoconsiste clusive lyof0 s.
theran ofA ortheran ofB .N owbr,= 0
theratio
: bi m
therw ords,
metricmatri ofran thereisatleast onenon-
forder . 2
cof ran . B yTheorem8. 4set
m P i , (t = 1 , 2 , . .. , m)
s n ot 0 . e t b l c p ^ = m . T h en b i f = m pi p .
b eo f ra n < g . H e n ce b k = j = 0 .
ofas ewmatri iseven9.
a nd b r = b sr . e t
m P i = -mi P , p = \ = 0 .
j p 2 t hi s im pl ie s
p p i.
, contrary totheassumptionthattheran o fA
ors.Theorem9.1.A mongtheminorsof
a tri A o forderntheree iststherelation5
. 27A | t
i , m + 2 , . . ., 2 m h = m + i , . .. , 2m
i , h = m + i , h 1 , m, h + i ,. .. , 2m .
ente lements. et ar, = a . Theoperation
ihrungindieDeterminantentheorie, p. 124.
e a ng e w. M at h . V o l . 72 ( 1 87 0 ) pp . 1 52 1 7 5.
e w. M at h . V o l .2 ( 1 82 7 ) pp . 3 47 3 5 7.
ebyG. A . B liss: A nn. o fMath. I V o l. 1 (1914)
. p r eu B . A k a d. W i s s. 1 88 2 I pp . 82 1 8 44 W e r e
3 9 7.
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athitrust.org/access_
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dDeterminants.
ofcolumnh byelementswiththesamefirst
nd subscriptm,andthenreplacesthe elements
eterminantbyelementswiththesame second
ssubscripth. C onse uently
I h
alto
4 = w i n t he s e co n d su m ma t io n . Fo r h = j , = = 0 .
symmetric. Thecoef f iciento fah , h= \ = , is
mh 8 au /
o fcolumnshand doesnota lterthise pression,
tireleftmemberreducesto1
o ne c e r s i d en t it i es w as g i ve n b y . c h en -
provedthemfrom now nidentitiesina lgebra ic
m e4statedthattheyare impliedinGrass-
u s de h nu n gs l eh r e 1 8 2 , p .
talllinearrelations amongtheminorsofa
nearlydependentuponthoseof ronec er,
dentsystems.H ealsoprovedthatno such
w matrices. Hisresultsaresignif icantincon-
ationsof ronec er sidentit iesbyMuir ,
licatedidentitiesamongtheminorsof
ronec er sinthesymmetriccase. A very
entitiesamongtheminors ofamatri was
. B eaver9.
oc . N a t. A c a d. c i. U . . A . V o l. 12 ( 19 2 ) p p. 3 - 4 .
a th . P hy s i V o l . 32 ( 1 88 7 ) pp . 1 19 1 2 0.
l . A m e r. M at h . o c . I V o l . 2 ( 1 89 ) p p . 13 - 1 38 .
h. A n n V o l .2 ( 18 8 ) p p. 2 09 2 10 .
eangew . Math. V o l. 93(1882)pp. 319 327.
o l . 3 (1 9 02 ) p p. 4 1 0 4 1 .
N a t . A c a d . c i . U. . A . V o l . 12 ( 1 92 ) p p . 39 3 3 9 .
. Math. oc. V o l. 2(1901)pp. 395 403.
m e r . Ma t h. M on t hl y V o l . 3 9 ( 19 3 2) p p . 2 6 2 7 .
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athitrust.org/access_
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dDeterminants.
ow edthatthereare ustn2 n+ i
norsofamatri . touf fer3showedthat(A J ,
nstitutesuchasystem, thesubscriptsindicatingdeleted
f fer4gaveamethodfore pressingthedeter-
nyorderintermsofnotmorethan14of its
der,andlater5 showedthatthedeterminant
afunctionof fourminorsofordern 1 andone
genera ltheoremonthee pressionofadeterminant
inantsw asprovedbyW. W . F le ner .
m10. 1. fA ise itherageneralmatri o r
,thereisno identity
ai ),
mialsintheelementsofA neitherofwhichis
of A i n de p en d en t a nd d ( A ) = f g . i n ce
ye lement, if auoccursin/ itdoesnotoccuring.
insa11arl, hencegiso fdegree0ineveryarl.
onta insarsarl, giso fdegree0ineveryar, and
lyaslightmodificationisre uiredtoe tend
ymmetricmatri 7.
theoremthat thedeterminantofan
isanirreduciblefunctionofthevariables8.
minantofthegenerals ewmatri ofeven
rationalfunctionof itse lements.
n 2,andtheprooffollowsby induction.
\ i s s e w of o dd o rd er a nd h en ce i ts r an i s n 2 a t mo st .
f b e th e co fa ct or o f ai f in 4 ; ; ; ; ; | | l . A s
5,
tionoftheelementsofA .B yassumption
areofarationalfunctionof thea^ , sothesamemust
beta enas1. B y the aplacedevelopment
a ^ a n = p ta in )2 .
altheoremwasprovedby .Z ylins i9.
ta inedf romA = (ars)by replacingacerta in
s . R o y . o c . o n do n V o l . 1 85 ( 1 89 3 ) pp . 1 11 1 0 .
o l. 38(1894)pp. 537 541.
er . M at h . o c . V o l .2 ( 1 92 4 ) pp . 3 5 - 3 8 .
h. MonthlyV o l. 35(1928)pp. 18 21.
t h. M o nt h ly V o l . 3 9 ( 19 3 2) p p . 1 5 1 6 .
n n . of M a th . I V o l . 2 9 (1 9 27 ) p p. 3 7 3 37 .
t iontohighera lgebra, p. 177. Macmillan1907.
bra ictheories, p. 259. C hicago192 .
B u l l . in t . A c a d. P ol o n. c i . 19 2 1 pp . 1 01 1 0 4.
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athitrust.org/access_
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dDeterminants.
of matrices,aswasclearlyshownby
sideredasa linearvectorfunction. . D. B ar-
neousvectorfunctionsofdegreep.H estates
rcterist icroote istsforthegenera lizedmatri .
beenatta inedine tendingtohigherdimensions
thesenseofhypercomple numberinw hich
inceeveryassociativesystemcanberepresented
almatrices,thislac ofsuccessis notsur-
ensionalarrayshavereceivedsomeattentionin
rformsandtensoranalysis.Theirimpor-
eneralizationsofran whichcanbeapplied
utativesystems.Determinantsofma-
uaternionswerediscussedbyH amilton4.
determinantofamatri o f uaternionsby
chtermin theorderoftheir columnindices.
dbi uaternionsandtri uaternionsasmatricesw ith
. tudy7gaveabriefdiscussionofmatrices
belongtoadivisionalgebraor non-com-
derableimportancefromthetheoremof
8thateverysimplea lgebracanberepresented
whoseelementsbelongtoadivisionalgebra9.
overadivisionalgebrain connection
sof lineare uationswereconsideredby
. H ey ting11, and0. O re12. The latterdef ines
ntby
^ O ) + a nA ^ > + . ..+ , ^ / ) ,
tionsofthehomogeneousleft-hand
)
e r . . M at h . V o l . 49 ( 1 92 7 ) pp . 8 9 9 .
a lif orniaPubl. Math. V o l. 1(1920)pp. 321 343.
. Math. Physics, Massachusetts nst. Techno l. V o l. 7
5 . - R i c e, . H . : b i d. 1 9 28 p p . 93 - 9 .
o f uaternions(A ppendi ). ondon1889.
. A m e r .M a th . o c .i l V o l . 5 ( 18 9 9) p p . 33 5 3 3 7.
oc . o nd on M at h. o c. I V o l . 4( 19 0 ) p p. 1 24 1 30 .
at h . V o l .4 2 ( 19 2 0) p p . 1 6 1 .
M . : Pr o c. o n do n Ma t h. o c . I V o l . ( 1 90 8 ) p. 9 9 .
brenundihreZ ahlentheorie , p. 120. Z urich1927.
. : Me s s. M a th . V o l . 55 ( 1 92 ) p p . 14 5 -1 5 2 P r oc .
V o l . 28 ( 1 92 8 ) pp . 3 95 - 42 0 .
A n n . V o l . 98 ( 1 92 7 ) pp . 4 5 4 9 0.
M a th . V o l . 32 ( 1 93 1 ) pp . 4 3 - 47 7 .
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ce uation.
right-e uivalentiftheirrightdeterminants
ricesA andB areright-e uivalentif they
of tw orow sorof tw ocolumns orifA is
iplyingtheelementsofacolumnon theleft,
ontheright, w ith = j = 0 orifA isobta ined
wto anotherroworonecolumnto another
ce uation.
t ion. fA isamatri o fordernovera
, A 2, . . ., A * ' constituten2+ 1setsofn2
arelinearlydependentin ThusA satisfies
11 - 1+ . . . + mf = 0
minimumdegreefi.W eshallcallfi theinde
ca l ar m a tr i i s 1 . v e ry m at r i e c e pt 0 h a s
0,m ).) f ' /.)
) m ( X ) + r ( X ) w h e re r ( ) .) = 0 o r e ls e r ( A ) i s o f
) = m ( A ) = 0 , r ( A ) = 0 . i n ce f i w as m i ni m al ,
nmume uationm(/ .)= 0isuni ue.
nimume uationwillbecalledthe norm
uation. Thematri obtainedf romA = (ars)
thecofactorA , ro fasrisca lledthead o int
a tr i A A j d ( A ) i s c a ll e d th e i nv e rs e o f A , w r it t en
o re m 7 .8 ,
* ( i4 ),
tisfiesane uation
C ^ * - 1 + . .. + C = 0 ,
goniermatriceswithe lementsinaf ie ldthenA
p l)=0 w hosecoef ficientsare in
consideredasan - thordermatri w hose
sin ofdegree^ k . tsad o int
- + D ^ -D -i + . .. +
ngew . Math. V o l. 84(1878)p. 1 3.
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athitrust.org/access_
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ce uation.
o fdegree^ k (n 1). Then
p 1 l - l + .. .+ p n
e
p( X ) ,
k - V = Z P n- X " I ,
. h m .
minate.By e uatingcoefficientsofthepowers
a ti o ns a r e ob t ai n ed . f t h e A - t h e u a ti o n is m u lt i pl i ed
eresults added,thesummaybewritten
- 1) -i y ,C k - A *
eoremof H .B .Phillips1whoproved
e - t h or d er m a tr i c es , a nd B . . ., B k a r e ma t ri c es
that
B k = 0 ,
j 1+ . . . + A M w heref t, . .. . & are in-
venis similartoFrobenius 2prooffor
attributestheidea toPasch3.
ymatri satisf iesitscharacterist ice uation
lton-Cayleytheorem,establishedfor
H amilton4, andprovedforn= 2, 3byA . C ay -
minthe generalcasewiththecomment
tounderta eitsproof.Manyproofs,more
beengiven . A . R . F orsyth7applieddifference
. B uchheimmadetheproofessentia lly in
statingthatit wasta eninconceptfrom
81.
e r. . M a th . V o l . 41 ( 1 91 9 ) pp . 2 6 2 7 8.
eu B . A k a d . W i s s . 18 9 p . 0 .
o l. 38(1891)pp. 24 49.
ectureson uaternions, p. 5 6 . Dublin1853.
o s . Tr a ns . R o y . o c . o n do n V o l . 14 8 ( 18 5 8) p p . 17 3 7 .
F o le p ol yt ec hn . V o l. 25 ( 18 7 ) pp . 21 5 2 4 C E u vr es
2 33 .
sMath. V o l. 13(1884)pp. 139 142.
t . V o l . 13 ( 1 88 4 ) pp . 2 6 6 .
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athitrust.org/access_
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ce uation.
orem14.2, itshouldbenotedthatB uch-
ts o f t he e u a ti o n X I A = 0 a r e ro o ts
e f io fA is^ n.
uationofA forthee uation X I A = 0
eftmemberiscalledthe characteristicfunction
+ t tX * - t n= 0
ationofA , thenttisthesumofa lltheprincipal
l i n X I A = 0 i s t h e su m o f th e d et e r-
a inedbysuppressingn irow sof A
umns.
)= au+ + anniscalledthe trace
ntionofA secondonly inimportanceto tn= d(A ).
uationofdegreenwith coefficientsin% is
t ionofsomematri o fordernw ithe lementsin
onbe
- + . .. + b n= 0 .
ar a ct e ri s ti c e u a ti o n. F or i f i n t he m a tr i X I B
lumnbyX andaddstothe(n lmth, multiplies
m th c o lu mn o f t he n e w ma t ri b y X a n d a dd s t o th e ( n 2 m th
pment, thedeterminantof thismatri isseen
n do n M at h . o c . V o l . 1 ( 18 8 4) p p . 3 8 2 .
s d a n al y se e t d e ph y si u e ma t he m at i u e V o l . ( 1 84 0 )
I V o l .1 1p p. 75 1 33 .
a th . V o l . 21 ( 1 87 ) p p . 17 8 1 9 1. a i sa n t, C . A . :
e V o l . 17 ( 1 88 9 ) pp . 1 04 1 0 7. R a d o s , G. : Ma t h. A n n .
24.
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ce uation.
( o r it s n eg a ti v e) a B e g l e it m at r i " . W e s h a ll
gitthecompanionmatri o f thee uation
educible in% , say
( - * y ,
t, le t
en t t ha t d (X I ) = f ( X ) . T h is m a tr i / w i ll
ri 2.
m inimume uation. Theorem15.1. et
erist ice uationofA , andleth(X )bethegreatest
i ) -r o we d m in o rs o f 7 .1 A . T h en
0
onofA . 3
= C ( X ) . T he n C A ( X ) = h (X ) ( X ) w he re t he e le me nt s
pr im e. i nc e / (A ) = C ( X ) C A ( X ) ,
X )h X ) ( X ),
o ,
) ( X ) .
( A ) 0 a nd m ( X ) g ( X ) w h er e m (X ) = 0 i s t h em i ni -
(f i) = ( X f ) ( X , u ), w eo bt ai n
X I ) -m( A ) = C ( X ) ( X I , A ) .
e nc e
) ( X I , A ) ,
h (X ) g (X ) ( X I , A ) .
ecance led. inceg(X )div ideseverye lement
eelementsof (X ) arere lative lyprime1g(X ) m(X ).
H e i d e lb e rg . A i a d . W i s s. V o l . 5 ( 1 91 8 ) p. 3 - M at h . Z .
5.
es u b st i tu t io n s et d e s li u a ti o ns A l g ^ b r i u e s, i v re 2
s 1 87 0 .
ngew . Math. V o l. 84(1878)pp. 1 6 3.
at h . A n n . V o l . 4 ( 1 90 ) p p . 24 8 -2 3 .
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athitrust.org/access_
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ce uation.
s t he c o mp a ni o n ma t ri ( o r t h e o r da n m at r i )
0 i s t he m i ni m um e u a ti o n of B ( o r ) .
m inimume uationofB isl i ew ise itschar-
t h e fi r st c o lu mn a n d la s t ro w o f A / i ,
1isobtainedw hosedeterminantisf reeofX X i.
n lmrow edminordeterminantsofX I is
uationof / isl i ew ise itscharacterist ice uation.
tfactorsofthe characteristicfunction/(/)
lein% coincidewiththedistinctirreduciblefactors
(X ).
rem15. 1,
) 0isarooto f / (X )= 0, soevery irreducible
X ). F rom(15. 1)
) .
, /, r,< ui.
m (X ) n .
)= 0isarooto fm(X )= 0, andevery irreducible
X ). 1
erd(A )orn(A )vanishes, bothvanish.
singularornon-singularaccordingasn(A )= 0
ogatory2if itsinde f i islessthann.
non-singularofordern andinde fi,A 1is
r ee f i 1 . 3
ationofA be
1 ' A - 1+ + m ^ X + n (A ) = 0 .
+ m1 A P - 2- h m f, -1 ) n (A ) .
.B utA A 1= A 1A = ,soA B = A A \
\ B = A \
singularoforder nandinde fi,theree ists
ib l e as a p o ly n om i al i n A o f d eg r ee f i 1 s u ch t h at
w, A * - H h m J ) ,A B = B A = n (A ) = 0 .
matri ise ithernon-singularoradiv isoro f zero .
)= 0isthe minimume uationofA ,then
fm(X ) andf (X )haveacommonfactoro f
n: A lgebrenundihreZ ahlentheorie , p. 21. Z urich1927.
c a d. c i ., P a ri s V o l . 9 8 ( 1 88 4 ) pp . 4 71 4 7 5 .
po l yt e ch n . V o l .2 5 ( 18 7 ) p p. 2 1 5 2 4 .
e in e a ng e w. M a th . V o l . 1 27 ( 1 90 4 ) pp . 1 1 1 6 .
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ce uation.
) ( A ) , f ( A ) = h ( A ) ( A ) , h ( A ) o f d e g re e ^ 1. T h en
/ i a nd ( A ) 4 = 0 . T he n
( A ) ,
en/ (/ ) isa lsosingular.
fm(X )and/ (A )sothat
( X ) f ( X ) .
(^).
) isa lsosingular, andh(A ) isnotaconstant.
,y, ,...)= / rational
)
terminates , y , z, . . . , w herepand arepo ly-
e X , B o f i nd e f i , C o f i n d e v , .. . b e co mm u ta t iv e
, B , C , . . . ) isnon-singular. Thenr(A , B , C , . . . )
canberepresentedasa polynomialofdegree
< f i i n B , o f d eg r ee O i n C , . . .
, C , . . . isbuiltupby theoperationsofad-
ca larmultiplication. inceA , B , C , . . .
ulta teachstepisuni ue. ince (A , B , C , . . .
stsandisapolynomia lin , andtherefore in
e p l = l p , an d r i s un i u e ly d e fi n ed . B y u s i ng
ofA , B , C , . . . , thedegreeof rmaybereduced
ts. etA beamatri o fordernw ithe lements
X I A be itscharacterist icfunction.
f% inw hich/ (A )= 0iscomplete ly reducible .
)= 0arecalledthe characteristicroots1.
,B ,C ,... becommutativematrices,andlet
onalfunction.Thecharacteristicrootsa1,...,anof
. canbesoorderedthatthecharacterist icrootsof
b 1 , cl , .. . ), . .. , /( , b , c n , . .. ) . Th i s or d er -
unction/.2
a s) ,P (o ) = J J ( a> b ) ,y (< w ) = J ( w c ) ,. ..
onsofA , B , C , . . . respective ly. Write
(a (, b , c , .. .) = / ( , b , c , .. .) f (f li ,b ' , c , .. .)
f ( , b , c , ., .) H = ( - ai )f i k . .. + i y b ^ g i i c. ..
k . . . T he re fo re
, c , . .. ) = < x ( ) + ( 3( y) + M y (z ) + . .. ,
,i , = i , . .. , v, . ..
ester.
eu B . A k a d. W i ss . 18 9 1 p p. 0 1 6 1 4 .
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ce uation.
aecommutative , thesetw opo lynomia lsgivee ua l
, y = B , z = C , . .. H e n c e
f (A , B , C , . . . ) . Thereforetheminimum
, . . .) , o fdegreean, ise ua ltoaproductof
ncludeallthe distinctfactorsofthecharacteristic
, B , C , . . . areorderedbyca llingthe i- th
f = 0 /( ( , < , c i, .. .) .
arried throughwhen/isa polynomial
1 , i n y of d e gr e e fi 1 , i n z o fd e gr e e X 1 , .. .
cients,andanorderingoftheroots of
ined. B y Theorem15. every rationa lfunction
obta inedbyspecia lizingthecoef f icientsof
gisthe sameforallrationalfunctions1.
ovedthatthecharacterist icrootsofA nare
hecharacterist icrootsofA . Thespecia lcaseforA
redby . . y lvester3. W. pottisw oode1
1arethereciproca lso f therootsofA . G. F ro -
1 . 1f irstforasinglematri andlaterinthe
errediscovered pottisw oode s7resultand
1878.
mwich9notedthatFrobenius theoremneednot
alfunction.
acteristicrootsofA B arethesameasthose
. 9thecoef f iciento f^A " - inthecharacter-
i s
. - B . p r eu B . A k a d .W i s s . 19 0 2 1 pp . 1 20 1 2 5.
. r e in e a ng e w. M a th . V o l . 30 ( 1 84 ) p p . 38 4
V o l . 12 ( 1 84 7 ) pp . 5 0 6 7 .
o u v . A n n . ma t h. V o l . i l (1 8 52 ) p p. 4 3 9 4 4 0.
. r e in e a ng e w. M at h . V o l . 51 ( 1 85 ) p p . 20 9 2 7 1 an d
eangew . Math. V o l. 84(1878)pp. 1 6 3.
. A c a d. c i ., P ar i s V o l . 9 4 (1 8 82 ) p p. 5 5 5 9 .
M ag . V V o l . 1 ( 1 88 3 ) pp . 2 7 2 9 .
. ' A . : P r o c. C a m b ri d ge P h il o s. o c . V o l . 11 ( 1 90 1 ) pp . 7 5
g .V V o l . 1 ( 1 88 3 ) pp . 2 7 - 2 9 .
b , c , ... ) = 0
c , .. .) .
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athitrust.org/access_
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ce uation.
nd(A 1, . . . , h i)rangeovera llf j se lections
eset1,2,...,nwithoutregard fororder.
nterchangingthesummationindices.
oremwithoutproof.A proofbasedupon
tyw asgivenbyH. . Thurston1. A proof
T u rn b ul l a nd A . C . A i t e n 2.
atthetheoremofFrobeniusaffordsan
Tschirnhausentransformation. etit
e uationw hoserootsaretherationalfunctiony
. e t B b e t he c o mp a ni o n ma t ri o f f ( ) = 0 .
p(B ) = 0 isthere uirede uation.
bra icintegra lroots, thee lementsofB arerationa l
o lynomialw ithrationa lintegralcoef f icients,
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ce uation.
+ A n t h e a d o i nt - tr a ce o f A 1 , s i nc e i ts s u m wi t h A 1
edef init ionofcon ugatesetby theomis-
andshowedthatforeveryA 1asetof generalized
ists, nota lw aysuni ue ly , how ever. ater2hegave
ndinga llsetsofcon ugatesforagivenmatri .
particularmatri B suchthatofB form
gatematricesinthesenseof Taber,whereto
nity.
tthefield generatedbytherootsofany
phicwiththefield generatedbythematric
acterist icroots. nthisparagraphgis
tA cdenote(ars), obta inedf romA by replacing
ugatecomple number.
ianifH = H C T.5A realhermitianmatri
w-hermitianif = C T. A reals ew-
ew .
U1= U T.7A realunitarymatri is
t or y i f V 1 = V , i . e . , if V 2 = 1 . 8
hastwoofthethree .propertiesinaset,
ary.
al,involutory.
volutory.
utonne9,thelasttwotoH .H ilton10.
atri isuni uelye pressibleA H +
nd iss ew -hermitian.
heorem5.3.
H + whereH ishermitianand iss ew-
arethema imaof theabso luteva luesof the
M a th . I V o l . 2 3 (1 9 23 ) p p. 9 7 1 0 0.
h. Physics, Massachusetts nst. Techno l. V o l. 10(1932)
er. Math. MonthlyV o l. 39(1932)pp. 280 285.
m e r . Ma t h. o c . V o l . 3 ( 1 93 0 ) pp . 2 2 2 4 .
. A c a d. c i ., P ar i s V o l . 41 ( 1 85 5 ) pp . 1 81 1 8 3.
e in e a ng e w. M a th . V o l . 1 22 ( 1 90 0 ) pp . 5 3 7 2 .
d . C i r c. m at . P al e rm o V o l . 1 ( 1 90 2 ) pp . 1 04 1 2 8.
n n . V o l . 13 ( 1 87 8 ) pp . 3 20 3 7 4. P r ym , F. : A b h . G es .
3 8 ( 18 9 2) p p . 1 4 2 .
c. Math. F ranceV ol. 30(1902)pp. 121 134.
eneouslinearsubstitutions. Ox ford1914.
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ce uation.
respectively , andifa= + P isacharacteristic
^ . nh, f3 ^ n .
i s s in g ul a r, t h er e e i s ts a v e ct o r ( ) = ( l , .. . , n )
oa l l 0 su c h th a t (A a ) ( ) = 0 . H e n c e
. ( , / = 1, 2 ,. .. . n)
a j ( } ,
a. i 5,. X j .
acting,
^ ^ i h.
f r i X , .
+ n) s m(V + + * ) ,
n h, f i * n .
racteristicrootsofan hermitianmatri are
= 0 , = 0 , a nd e ve ry / | = 0 .
tsofareal symmetricmatri areall
hy2. Many laterproofshavebeengivenby
uchheimetc. Thee tensiontomatricessuch
adebyH ermite3andresultedinsuchmatrices
racteristicrootsofa s ew-hermitianmatri
.
a = 0 .
ors ewmatricesbyA .C lebsch5and
. H i r sc h : A c t a ma t h. V o l . 25 ( 1 90 1 ) pp . 3 7 3 7 0.
n c ie ns x e r c is es . 18 29 1 83 0 C o l l. W o r s I V o l . 9 pp . 17 4
c a d. c i ., P ar i s V o l . 4 1 (1 8 55 ) p p. 1 8 1 1 8 3.
mericieA lgebrepp. 133 179. Messina1921.
in e a ng e w. M a th . V o l . 2 ( 1 8 3 ) p p. 2 3 2 2 4 5.
. - B . p r eu . A k a d . W i ss . 1 87 9 .
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ce uation.
thelasttheoremis real,then
# ,) / a r e al l r ea l , th e i ne u a li t y (1 8 .3 ) m ay b e a pp l ie d
1 i ( n- i) v i. -
< 2 3> J k . 1
wasprovedby .B endi son2,andthe
eemstohaveinspiredthew or o fH irsch.
a- -if beacharacteristicrootof A = H + .
emistheleast andMthegreatestofthe char-
hermitianmatri H bedenotedbyhrs.
ueof theratio
e independentcomple variables. Thegreatest
)assumesarecharacterist icrootsofH, for
f + f y , th e c on d it i on s
2, . .. , )
f ^ x ^ = 0.
mvaluewhich/ ( )assumesandMisthema i-
otM. 3
plicite pressionfor and/ f romw hich
smaybederived.
ine ua lit iesbyanothermethod.
arebyA . H irsch: 1. c.
c t a m at h . V o l .2 5 ( 19 0 1) p p . 35 9 3 5 .
son, thecomple casebyHirsch: 1. c.
t h. V o l . 30 ( 1 90 ) p p . 29 5 3 0 4.
n n . V o l . ( 1 90 9 ) pp . 4 88 - 51 0 .
mati . MacDuf fee. 3
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ce uation.
thatifA isacharacterist icrooto fA andifm
testcharacteristicrootof thehermitian
n m= S X X M .
heelementsofA areallrealandpositive,
whichisreal,positive,simple,and greater
other characteristicroot.
ofthe minimume uationofanhermitian
H hastheminimume uation
) ,
- 1h X ) .
) 2.Thematri H 1= hr,)= m1(H )ishermitian,and
0 . B u t
(H) = 0. B utm1(X )iso f low erdegreethan
mption > 1leadstoacontradiction3.
ofunitarymatrices.Theorem19.1.The
tarymatri areofabsolutevalueunity.
c r oo t o f th e u ni t ar y m at r i U , + i l i s a
r U + U 1 = 1 7 + UC T , a n d i x i s
m it i an m a tr i U U 1 = U U C T b y T he o re m
laries18. 31and 8. 32,
i x = 2is,
tis,
x = r i s,
sgivenbyR . B rauer5. fU= (ur, ) is
1, sothee lementsofUareboundedinabsolute
retrueof thecoefficientsofthecharacteristic
sroots. B utU1andU are li ew iseunitary ,
sof Ularethereciprocalsof thoseofU,
U arethe - thpowersof thoseofU . Unless
U wereofabsolutevalueunity,somepositive
d bemadearbitrarilylarge,thusleadingto
l. A m er . M at h . o c . V o l . 34 ( 1 92 8 ) pp . 3 3 3 8 .
eu B . A k a d . W i s s . 19 0 8 pp . 4 71 4 7 .
M . : A n n . o f Ma t h. I V o l .2 7 ( 19 2 ) p p . 24 5 2 4 8.
uMath. . V o l. 28(1927)p. 281.
u M a th . . V o l . 30 ( 1 92 8 ) p. 7 2 .
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n t eg r al M a tr i c es .
C T = V C T V , a n d if i s a ro ot o f U V \ = 0 ,
w here^ isthegreatestinabso luteva lueand
lueof thecharacterist icrootsofV . ach
ncipa lm inorofaunitarymatri iss lin
ple characteristicrootsofanorthogonal
a lpa irs2.
e uationofanorthogonalmatri hasrea l
rootsoccurincon ugatepairs, w hichby
alpairs.
oremhavebeengivenbyA . . R ahusen3
connectionw iththisla tterpaperseea lsoG. V ita li5.
a t if A + l = 0 h a s r e ci p ro c al r o ot s , A
utory.
aif thecoef ficientse uidistantf romthe
e u at io n of A a re e u al , A + A h - - l = 0
thesecoefficientsoccurin pairswithopposite
A + l = 0 h as a ll r ea l ro ot s.
n t eg r al M a tr i c es .
sina principalidealring.A commutative
ois calledadomainofintegrity.A domain
nt1 inwhicheverypairof elementsnot
mondivisorrepresentablelinearlyinterms
principalidealring9.
, anumberw hichdiv ides1isca lleda
whereuis aunitisreciprocal,and two
darecalledassociates.A setofnumbersof
ssociatedbutsuchthat everynumberof
hemiscalledacompleteset ofnon-associates
egersand 0constituteacompletesetof non-
tionalintegers.
her0noraunit isprimeorcompositeaccording
esnotimply thatborcisaunit.
B r a u e r: T o ho u M a th . . V o l . 3 2 ( 19 2 9) p p . 44 4 9 .
, p ur e s ap p l. V o l . 1 9 ( 18 5 4) p p . 25 3 2 5 .
i s u n di g e O p g av en V o l . 5 (1 8 93 ) p p. 3 9 2 3 9 4.
n . Ma t . t a l V o l . ( 1 9 27 ) p p. 2 5 8 2 0 .
. Ma t . t a l. V o l . 7 ( 1 92 8 ) pp . 1 7 .
o l l . U n. M at . t a l. V o l . ( 1 9 2 8) p p . 5 - 9 .
c c a d. n az . i nc ei , R e nd . V I V o l . 8 (1 92 8) p p. 6 4 6 9 .
u M a th . . V o l . 32 ( 1 92 9 ) pp . 2 7 3 1 .
oerneA lgebraV o l. pp. 39and 0.
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n t eg r al M a tr i c es .
faprincipal idealringisa euclideanring
operties:
ye lementa(e ceptpossibly0)o f thering,
gers(a)called thestathmofa.
ersaandb, b^ 0, theree isttw onumbers
b + r , a nd e i th e r r = 0 o r e l s e s( r ) < s ( b ) .
ple numbersa+ ib,astathmis
mialdomain% ( )o facommutativef ie ld r,
alservesas astathm.Forthetrivialinstance
enas1foreverya. A euclideangreatest
istsineveryeuclideanring.
roperifit isnota fieldandifa stathm
hats(ab)= s(a)s(b)foreveryaandb. ince
)s(b), e ithers(b)= 1foreverybsothatdiv isionisa lw ays
d, ore lses(0)= 0. C onverse ly lets(a)= 0.
reveryb, b= a , and isaga inaf ie ld.
)= s(1)s(b), e ithers(b)= 0(and(5isa f ie ld)or
nit, anduv= i. Thens(u)s(v)= 1 sothat
s(a)= 1, a isaunit, f orthestathmof the
nynumberbyamust be< 1andhencebe 0.
nrings(a)= 0ifandonly ifa= 0,s(u)= i
nds(a)= s(b)ifandonly ifaandbareas-
theseto fa ll - thordermatricesw hoseelements
lring sub ecttotheoperationsofaddit ion
3. 2 { isaringbutnotaprincipa lidea lring.
sca lledunimodularoraunitmatri if andonly
U o f 9 tt s u ch t h at U U = .
matri ifandonlyif d(U)isaunit of
U)d(U )= 1sothatd(U)isaunitof
andd(U)isaunito f ty, thenU1isin D and
definit ion.
A ofW tisa divisorofzeroif andonlyif
matri B o fTheorem15.4(suchthatA B
in 2 R .
adiv isoro f zeronoraunit isca lledprimeif
impliesthate itherB orC isaunit. Matrices
unitsnorprimesarecalled composite.
ositematri canbee pressedasaproductof
primes.
3 . . .,
d e rb u rn : . r e in e a ng e w. M a th . V o l . 1 7 ( 1 93 1 ) pp . 1 29
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n t eg r al M a tr i c es .
atri implies
) d (A 3 ) . .. .
aunit. Thatis, eache lementinthese uence
. d(A 2)d(A 3)d(A 3). . .
receding. uchase uencecanconta inbut
s1.
odularmatrices.Theorem21.1. et
numbersofaprincipa lidea lringw ithgreatestcom-
istsamatri ofdeterminantdnhavinga1,a2,...,an
ueforn = 2. upposeittrueforn 1,
whichhasa1, a i, -1asitsf irstrow , and
g. c. d. d -1of 1, a2, .. . , an - . Determinep
a n = d n. C o n s i de r t he m a tr i D o b t a in e d by
htbya , 0, . . . , 0, 0andthenbelow by
2 A * n -1 . - n - 1 R > - 1. P. Th en d D n) = d n
givenby . Weihrauch4, B ianchi5, and
genera lly thatamatri canbefoundw ith
, an2, annandadeterminant+ 2an2-
sarearbitrary.
eralizedasfollows.A p.narrayofrational
, andtheg. c. d. of thep- row edminordeterminants
betoaddn prow sof integerstothisarrayso
earraysha llbeofdeterminantd. H . . . m ith8
9provedthistheoremanddetermineda llpossible
hortproofby induction.
. Tw omatricesA andB areca lledle f t
saunitmatri UsuchthatA = UB . The
beusedtoe pressthisre lationship, w hichpossesses
e ua lity re lationship, namely10:
d er n e A l g eb r a V o l . p . 4
3, G. isenste in: . re ineangew . Math. V o l. 28
74. F oranyn, C . H ermite : . Math, puresappl. V o l. 14
0 .
o c . Ma t h. F r an c e V o l . 50 ( 1 92 2 ) p. 1 0 0 1 1 0.
M a th . P hy s i V o l .2 1 ( 18 7 ) p p . 13 4 1 3 7.
su l la T eo r ia d e i N u m er i A l g e b ri c i, p p . 1 7 .
m e r. M at h . Mo n th l y V o l . 31 ( 1 92 4 ) pp . 1 1 1 2 .
ng e w. M a th . V o l . 40 ( 1 85 0 ) pp . 2 1 2 7 8.
Ph il os . Tr an s. R o y . o c. o nd on V o l . 15 1 (1 8 1 1 8 2 )
. : A n n . F ac . c i . Un i v. T o ul o us e V o l . 4 (1 8 90 ) p p. 1 1 0 3.
r. Math. oc. V o l. 37(1931)p. 538.
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n t eg r al M a tr i c es .
r A = 5 o r A = f = B .
A .
i m p li e s B = A .
a n d B = C , t h en A = C .
orthere lationA orA = B U.
operationsupontherowsofamatri can
plyingthematri ontheleftbyanelementary
i obtainedbyperformingtheelementary
tionupontheidentitymatri /.
worows.
ee lementsofarow byaunit of
mentsofany row of t imesthecor-
yotherrow,where isin
isaunitmatri w hose inverse isan
esametype. fB isobta inable f romA bya
rytransformations,B = A .1
atri A withelementsin< J 3isthe leftassociate
sabovethemaindiagonal, eachdiagonale lement
mofnon-associates,andeachelementbelowthe
rescribedresiduesystemmodulothediagonal
w illbesa idtobe inH ermite snormalform.
e lementsin ithereverye lementof the
atleastonenon-zeroelementwhichbya
nbe putintothe(n,n)-position. etdnbe
thelastcolumn,andsupposethat
nn = 4 .
e istsaunimodularmatri Uhav ing , b2, .. . , bn
UA = A hasdninthe(n, mposit ion, w here
ra in. B ysubtractingapropermultipleof the lastrow
w s, amatri A 1isobta inedw hose lastco lumn
hemaindiagona l.
th c o lu m n ei t he r e ve r y el e me n t of t h e fi r st n 1
ationof thef irstn 1row sanon-zeroe lement
i , n m p os i ti o n. e t d n- 1 b e a g. c .d . o f
, n -l . n - l ,n -l a nd l et
+ ^ n - l n -l ,n -l = < ^ n - l
e r: M .- B . p re uB . A k a d . W i ss . 18 6 pp . 59 7 1 2.
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n t eg r al M a tr i c es .
1hasO' sabovethemaindiagona linthe last
1, n mposit ion, andeachelementabove
sothatthesecanbemadee ualto0byelementary
essiscontinueduntilamatri isobtained
bovethemaindiagona l.
e inanyprescribedsystemofnon-associates,
multiplyitby aunit.Thisis accomplished
mationofthesecondtype.
leof the( 1mthrow fromthe - th
nbemadeto lie inanyprescribedresiduesystemmodulo
yelementcanbereducedmodulothediagonal
nderstoodthata= bmodO ifandonly if
= j = 0, thenormalformofH ermiteisuni ue.
n= ,buttheprocess isgeneral. uppose
andB
nd = ( lrs)
= 0 , ^ 2 3 = 2 3 a 33 = 0 .
0 , = j = 0 a n d l 1 3 = = 0 . i m il a rl y e ve r y el e me n t
gona lis0.
f^ , Z u, l22, ^ 33area llunitso f5p. Then
dsincea iiandbubelongtothesamesystemofnon-asso-
22 + 3 2
systemmoduloa22,l32= 0.
s = .
non-singularmatri w hosee lementsare
associateofamatri whosediagonalelements
0 f o r r < i , a n d 0 ^ a r i < a u f or r > i . T hi s
aselementsinaeuclideanring ,thereduction
omplishedbyelementarytransformations.
e lementsin . ithereverye lementof the last
ast onenon-zeroelementwithminimum
ninterchangeofthe rowscanbeputinto
fanndoesnotdiv idesomeain, set
s(ann))
in e a ng e w. M at h . V o l .4 1 ( 18 5 1) p p . 19 1 2 1 .
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n t eg r al M a tr i c es .
nsformationofthethirdtype,ain canbe
rchangerowsifnecessarysothat theelement
nisofminimumstathmandproceedas before.
eeveryain.Theproofnow proceedsasin
modularmatri withelementsinaeuclidean
itenumberofelementarymatrices.
yTheorem22. 3theree iste lementary
C / = V ,
aandreduced. inced(U )isaunito f , each
saunito f , andmaybeta entobe1. ince0
temofresiduesmodulo1,U = .Then
.. J E * ,
tarymatri .
unimodularmatri w ithe lementsinaeuclidean
mberofunitsis aproductofa finitenumber
iteset.
lintegersby ronec er1.
modularmatri withelementsinaeuclidean
cesof thetypes
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n t eg r al M a tr i c es .
alintegralelementsandofdeterminant1 is
namely
sors. fthreematriceswithelements
are inthere lationA = C D, thenDisca lled
dA isca lleda le f tmultipleofD. A greatestcom-
)Dof tw omatricesA andB isacommon
multipleofeverycommonright divisorofA
onlef tmultiple(l. c. l. m. )o f tw omatricesA andB
hich isaright divisorofeverycommon
.
rofmatricesA andB withelementsin%
ssible intheform
^
roofo fTheorem22.1, aunimodularmatri U
uchthatthe g.c.d.oftheelementsofthe
nthe(n, n)-posit ioninUF. Thenelementary
eto0everyelementof thiscolumnbelowann.
uedto obtainane uation
sunimodular.Thus
D
ghtdiv isoro fA andB isarightdivisoro fD.
, theree istsamatri = X 1w ithe lementsin
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oc i at e d n t eg r al M a tr i ce s .
rofnon-singularmatricesA andB with
. c. l. m. Muni ueuptoaunit le ftfactor.
nB = 0
fore
ofA andB . fM1isanotherc. l. m. the ir
Ml
tsac. l.m . M2suchthatM= H M2. uppose
.
,-X MB = H L B ,
enon-singular,
= H L .
2 + . ^ 22 ^ 22 = H [ K Y 1 2 Y 2 i , so H i s a ui ut ma tr i ,
fA f1. 1
denoteann- thordermatri w ithe lementsina
F oreverye lementmof theree istmatricesQ
1) A = m Q o r e l s e (2 ) A = m Q + R w h er e
mn ).
he le ftbyaunimodularmatri , itcanbe
rmalform. DetermineQ = ( r, ) , R = (rrs)such
r i ,
s ( m )f or > / , wh il e 0 < s (r if ) ^ s ( m) f or ' = ' .
) = * ( ) ,
r M .. . rn n = s ( r l1 ) s (r 22 ) .. . s( rn ) < s (m ) n = s (m n) ,
andeveryothere lementofR is0, i = m
andsomeelementofR be low themaindiagonal
otheoremsaredueinessenceto . C ahen: Th^orie
aris1914, andintheformherepresentedtoA . C hate let:
is1924.
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n t eg r al M a tr i c es .
ainform(2). etthelastcolumnhavinga
hemaindiagonalbethet-th, andletr ibe
hatcolumn. A ddrow torow i. Then
1 wh er es d (R j ) < s (m n) .
, t he nA = m U Q 1 + U R 1 w he re s d (U R j \ < s m n) .
ndB arematriceswithelementsina proper
d ( B ) = = 0 , t he r e e i s t m a tr i ce s Q a n d C s u ch
a n d ei th er C = 0 o r el se 0 < s d (C ) < s d (B ) .
istmatricesQ andR suchthat
,b = d B ) ,
e 0 < s d (R ) < s ( bn ). f R = 0 , A = Q B a n d
= 0 . f + R = A B A - bQ = A B A - Q B B A
= C B A . T he n
B A ,
s d(C ) s d(B A ) = s i(C ) s^ " - 1 = s d(C ) s(ft) " - 1.
) = s i (B ) .
ereprovedforrationalintegersby .G.du
dedby thismeanstoestablishthee istenceof
. e t bea linearformmodulo forder
ing91. Thatis, consistso fa llnumbersof the
an n .
dependentlyover9 , andthee sare linearly
to R . Thee sareca lledabasiso f .
foranyotherset
> % , ( ' , /= 1 .2 ,. .. , )
odularw ithe lementsin9 isa lsoabasisfor ;
onofthee sisa linearcombinationofthe
onversely,everytwobasesofalinearformmodul
sformation.Thefollowingdiscussionisrelative
. ., enof .
ar f o rm s u bm od u l of o r de r n o f , 2 a nd l e t h a ve
n. Then
' . / = 1. 2, .. ., n)
j schr. naturforsch. Ges. Z urichV o l. 51(190 )pp. 55
lidealring, everysubmodulo f2isa linearformmodul.
eneA lgebraV o l. I p. 121.
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n t eg r al M a tr i c es .
on-singularmatri w ithe lementsin9 . We
G1isassociatedwiththebasisA , , X 2, . . ,
rmatri G1determinesinthisw ayabasis
f 2.
, f it , . . ., f in isa linearformsubmodulo forder
r y nu m be r o f 2 i s i n fi , a n d
g k e .
dwiththebasisfa, fi2,finof 2isC G1,
armatri w ithe lementsin9 . Thisproves
contains 2ifandonly ifG1is arightdivisor
uls x and 2aree ua lif andonly if
C 2 G 2, t h en C 1 C 2 = . s o th a t C 1 a n d C 2
tri G1correspondstothemodulQ1 (G1 iC x ),
sdeterminedonlyupto aunitleftfactor.
rincipalidealringTheset ofnumbers
1and 2constituteamodul ica lledthe
dul(orlogicalproduct)ofthe twomoduls !
sobedef inedasthatsubmodulo f21and 2w hich
ubmodulo f 1and 2.
tainedineither 1or 2orboth,to-
differences,constitutesa modul2mcalled
modul(orlogica lsum)of 1and 2. tmayalso
conta ining 1and 2w hichisconta inedin
1and 2.
1,G2~ 2,Gd^ 2d,Gm~ m.ThenGd
,andGmis thel.c.l.m.ofG1andG2.
of theg. c. r. d. andl. c. l. m . foreachisdetermined
samelatitudeofdefinitionas thatofGd
directlyfromTheorem24.1.
swithrationalintegralelementsto the
gepartduetoA . C hate let1. Hisw or is
s, econssurla th^ oriedesnombres, Paris
nsfinis,Paris1924.
aringw ithunite lement, andlet bea linear
9 whichisalsoa ring,andwhoseelements
seof9 . A ninstanceofsuchasystemisadomain
ociativealgebrainthesenseofDic son2.
,A n n . fi c ol e n or m . l l V o l . 2 8 (1 9 11 ) p p. 1 0 5 2 0 2
ParisV o l. 154(1912)p. 502.
lgebrenundihreZ ahlentheorie , p. 154. Z urich1927.
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n t eg r al M a tr i c es .
nstantsofmultiplicationof beci lc, anddef ine
whichisclosedundermultiplicationon.theleft
a lleda le f t ideal1. im ilarly theremaybedefined
deals.
of is aleftidealif andonlyifits cor-
tisfiestheconditions
1 , 2 , .. ., n )
sw ithe lementsin9 .
, . .. , X n constituteabasisfora le f t idea l% w here
5 i s o f th e f or m
k i gi e ,
iso f theform
ev e ry s l a nd i , t he r e e i s t nu m be r s dr o f 9 s u ch
i c l h eh = d rg rt et .
early independent,
d rg rh .
s t va l ue s d p r o f d r wh e n sl = d l p an d i 8 i .
~ 2 ,d pt rg rh ,
d pr , ). ( P = 1 , 2 , .. . , )
onissuf f icient. etdp randg j benumbers
veconditions.Define
^ k iX iisevidentlya modul. etsbeany number
r er = 2 i ( du, X s
chisthereforealeftideal2.
rrespondencebetweenidealsinanalgebraic
aionalintegra le lements. fX l, X t, . . . , . H
oerneA lgebraV o l. p. 53.
rans. A mer. Math. oc. V o l. 31(1929)pp. 71 90.
co lenorm. llV o l. 28(1911)pp. 105-202.
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athitrust.org/access_
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i n a n d = l l , X 2 , . . ., X n i s a d ia g on a l
anecessaryandsuf ficientconditionthatA E A 1
artf romadiagonalmatri asafactor, corre-
l.
principa lidealring f tw o lef t idea ls^ i
basesA 1, . . . , X nandf il, . . ., f inrespective ly , theset
isev identlyamodul. ince isaprincipa l
mmodul. t isreadily seentobeclosedunder
yanumberof , so it isa le f t ideal. The
heproductofthe ideals3iand% 2inthatorder.
rrespondencebetweenmatricesand uad-
tanceofthecorrespondenceofthis paragraph,
orrespondingtotheidealproduct thesecond
roductofthematricescorrespondingto the
morphismofidealmultiplicationwith com-
rms.
ngtotheproductofthe twoleftideals31
thematrices
n)
Q2, andX 1, A 2, . .. , X n isabasiso f v
renumbersofana lgebraicf ie ldofordern, aminimal
)isreadilydeterminedfromits associated
g.c. r. d. o f
c ) .3
r ic e s. e t A = P B Q , w h er e e ac h m at r i h a s
dea lring J J . ThenA isamultipleofB .
isamultipleof B ,theg.c.d.dtof thei-rowed
dividestheg.c.d. dlofthei-rowedminordeter-
romTheorem7.9.
withelementsin aree uivalent A = B )
dularmatricesUandV suchthatA = UB V .
c o le p o ly t ec h n. C a h . 4 7 ( 18 8 0) p p . 17 7 2 4 5.
. C . MacDuf fee: B ull. A mer. Math. oc. V o l. 37
a t h. A n n . V o l . 10 5 ( 19 3 1) p p . 6 3 6 6 5 .
e a ng e w. M a th . V o l . 1 14 ( 1 89 4 ) pp . 1 09 1 1 5.
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nceisdeterminative,refle ive,symmetricand
22. )Thepresentchapterhastodow iththoseproperties
iantunderthis relationship.
= B , everyg. c. d. dto f the i- row edminordeter-
tedwitheveryg.c.d.d ofthei-rowedminordeter-
ontherow sofamatri a redefinedasin 22,
bymultiplyingthematri ontheleftby a
ementaryoperationsonthecolumnsaredefined
achbeingaccomplishedbymultiplyingthe
unimodularmatri . The inverseofane lemen-
ntaryoperationofthe sametype.
matri A ofran withelementsin^ ise uiv-
A x , ht, . . ., he , 0, .. . , 0 w hereA i1. 2
alled mith snormalform.
therow sandco lumnscanbeshif tedbyelementary
eminordeterminantoforder intheupper
0. ThenasintheproofofTheorem22. 1, thee lement
anbemade= j = 0 andag. c.d. o f thee lementsof
entsofthe firstcolumnbelowthefirstrow
sbyelementary transformationsontherow s. f
ndsinthe (1, mpositiondivideseveryother
theseothere lementscana llbemadeO' sby
onsonthecolumnssoasnotto disturbthe
f theyarenota lldiv isibleby thise lementa11,
heg.c.d.oftheelementsofthe firstrow,
ewerprime factorsthanan.Theprocess
ementinthe(1, mpositionisobtainedwhich
ntofthefirst rowandeveryotherelement
eeverynumberof% isfactorable intoaf inite
geis reachedinafinite numberofsteps3.
stn 1row sandcolumns, thenw iththe
ndco lumnsetc., A canbereducedtoane uiva lent
, 4 = 0 .
elementofMw erenot0, itcouldbeshif tedinto
posit ion, andA w ouldhaveanon-vanishingminor
i.
P hi l os . M ag . V o l . 1 (1 8 51 ) p p. 1 1 9 1 4 0.
Ph il os . Tr an s. R o y . o c. o nd on V o l . 1 I (1 8 1 1 8 2 )
erneA lgebraV o l. I p. 124.
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athitrust.org/access_
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umn3, . . . , co lumn toco lumn1, Dis
rem22. 1, there isaunimodularmatri Uw hich,
cesh1bytheg.c. d.ofhl,...,he.Thenew
mentahomogeneouslinearcombinationof
isdivisiblebythe newh1.A gain
m hl, A 2, , A J w herenow h1divides
tlhi+ 1, = 1, 2, . .. , (> 1.
w ithe lementsinaring ' , w ithunit
zero,in whichbothleftandright division
hatis,astathm isdefinedforeverynumber
, andforeverypa iro fnumbersaandb, b4= 0, there
, r, r , s uc h th at
r s( r) < s ( ) ,
o r s( / )< s ( ) .
' iscommutative , it isaeuclideanprincipa lidea lring( .
' i s p ro p er .
mationisoneoffivetypes:
mentsofanyrowofthe productsofany
thecorrespondinge lementsofanotherrow, be ing
mentsofanycolumnoftheproducts of
by thecorrespondinge lementsofanotherco lumn,
tfactor.
owsor oftwocolums.
meunitfactorbeforeeachelementofany row.
meunitfactoraftereachelementof any
yoperationscanbeeffectedby multiplying
ontheleftor ontherightby acertainelementary
lementarymatricesisca lledaunitmatri , in
nceptofdeterminantis notdefinedfor
anon-commutativering.
1hasprovedthatifA hase lementsin ' ,
esPandQ suchthat
, 0 ,. . .. 0 ,
M . : . r e in e a ng e w. M at h . V o l . 1 7 ( 1 93 1 ) pp . 1 29 1 4 1.
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athitrust.org/access_
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r an o f A , a n d i f ( i s p ro p er , i s b ot h a r ig h t
1
properhadbeengivenessentiallyby . .Dic -
result ingdiagona lmatricesarefactorable intoprime
art fromunitfactors,thesameis truefor
sin@' w hichareof ran n.
ndelementarydivisors. etA beamatri
palidea lring , andlet
,0
lform(Theorem2 . 2). thasbeenseen(Theorem
of the - rowedminordeterminantsofA isas-
o f the - rowedminordeterminantsofD.
di= h1h2...hiofthei-rowedminor
destheg. c. d. di+ 1= h^ h^ . . . hi+1 of the(i+ 1m
sofA .
,h2= d2 dl,h3= d d^ , arecalledthein-
eyare invariantsunderthere lationofe uiv -
duptoa unitfactor.
everye lementne ither0noraunitcanbe
ceptforunitfactors)intoaproductofpow ers
, p h .
ponentsofeachprimefactorformase uence
. .. e u. ( 1= 1 , 2, . .. , )
f asarenotunitsareca lledthee lementary
strass . Theyaredef ineduptoaunitfactor.
resimpleifeach isaprime4.
B ifandonlyif A andB havethesameelementary
.
sameinvariantfactors, theycanbereduced
andhencearee uiva lent. f theyaree ui-
einvariantfactors,fortheseare invariants.
minetheelementarydivisorsuni uely,and
ricesA andB withelementsinacommutative
lentifandonly if theyhavethesameran .
rden: 1. c.
lgebrasandtheirA rithmetics. Univ . o fC hicagoPress
d er n e A l g eb r a V o l . p . 5 .
- B . p r eu B . A k a d . W i s s . 18 7 4.
mati . MacDuf fee. 4
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mentofge cept0isaunit, andanormal
maybechosenw herethenumberof l sis
divisorsisoneof theoldestandmost
anchesofmatrictheory.Theliteratureis so
erisre ferredtoP . Muth sTheorieundA n-
tarteiler1fortheearlypapers.Thetheorywas
rass2forthepolynomialdomainofthecomple
mith3andG. F robenius4formatricesw ithrational
Frobenius5formatriceswithelementsin
latergavearationaltreatmentofthe
edthatifA andB haverationalintegra le lements,
dMthe irl.c. l. m. , thenMA 1andMB 1
meinvariantfactorsasB DlandA D1.
r i . e t A b e a m at r i o f r an w i th
a lringB yTheorem2 . 2, A isaproduct
onalmatri
. .. . 0 .
ducto fmatricesof thetype
actorofhi,and adiagonalmatri
ran . Thematrices 1, . . . , pi,. . . , i have
rethereforeirreducible8.
thefo llow ingdecomposit ionforaunimodular
af ie ldforthecase 4= 0:
onw hen = 0.
edthefactorizationofamatri intoe lementary
- B . p r eu B . A k a d . W i s s . 18 8 p p . 31 0 3 3 8.
P ro c . o n do n Ma t h. o c . V o l .4 ( 1 87 3 ) pp . 2 3 - 2 53 .
eangew . Math. V o l. 8 (1879)pp. 14 208.
r e in e a ng e w. M a th . V o l . 88 ( 1 88 0 ) pp . 9 1 1 .
p r eu B . A k a d . W i ss . 1 89 4 p p. 3 1 4 4 .
. A cad. ci. , ParisV o l. 177(1923)pp. 729-731.
j schr. naturforsch. Ges. Z urichV o l. 51(190 )pp. 55
. -B . p r eu B . A k a d. W i ss . 18 89 p p. 4 79 5 05 .
o u v. A n n . M a th . l l V o l . 1 5 ( 18 9 ) p p . 34 5 -3 5 .
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thateverymatri isaproductofe lementary
i ( ) isobta inedby replacingthe0inrow i
en t it y ma t ri b y . k ( ) i s o bt a in e d by r e pl a ci n g
m n o f t he i d en t it y m at r i b y . " i s t he
rowscycliclypermuted.
everysecondorderintegralmatri isa
nimportantinstanceofaprincipal ideal
main (A )o fa llpo lynomialsin w ithcoef f icients
Theelementsof% (e cept0)aretheunits
) iseuclidean, forifaandb= j = 0aretw onumbers
sttw oothernumbers andrsuchthat
eriso f low erdegree inX than . f is
, thecomple f ie ld), theprimesin^ J (A )are
.
s0 + a rs lX + + a rs l ) w it h el em en ts i n
omia lin ,
o )+ (O r .i )A + + ( ar s ) X 1 ,
triceswithelementsinThematri A
4 = 0 . t i s p r op e r if i t i s of d e gr e e a n d
ndB arematriceswithelementsin^ J (A ),and
, thentheree istmatricesQ andR (Q 1and
R , A = Q 1 B + R l ,
1 = 0 ) o r el s e R ( R j ) i s o f de g re e < l .
.. + A 0 , B = B { X l + . .. + B 0 ,l < k .
0 , t he e u at io n B l X = A k h as a s ol ut io n X = C * - .
k -iX k -lisof degree 1atmost.C ontinueasin
a remainderisobtainedofdegree< Z .
ndB areproperofdegrees and respectively,
er e e i s ts a m at r i Q a n d tw o ma t ri c es R 1 a n d R 2 ,
ectively,suchthat
Q B + R , , P2 = A Q + R 2 , ^ < l ,r 2< k *
hr. Ges. Wiss. Gottingen1909pp. 77 99.
c c a d. n a z. i n ce i , R e n d. V V o l . 23 I ( 1 91 4 ) pp . 2 08 2 1 2.
erneA lgebraV o l. p. 198.
p r eu B . A k a d . W i ss . 1 91 0 p p. 3 1 5 .
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athitrust.org/access_
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2sothat
P1 = Q ^ B + R 1 ,
ree< / , andR 2is0 orofdegree
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umof thematricesA l, A t, . . . , A k , andw ill
.
h A k .
A ise uivalenttothematri
5n - (X ) + + B . ( X ),
X ) , . . ., h n (X ) i s t he m i th n o rm al f o rm o f X A ,
r w hose invariantfactorsarea ll i sbutthe last
i = = 1 , . .. , 1, f
P n . , Q = Q n + Q n -l + . . .+ Q n - ,
noftherows andcolumnsofPB Q gives
maybechosentobe
V , - 1 H
educible insay
.
n t he f o rm X J , w h er e / i s th e o r da n f or m
eeC oro lla ry15.1. )
yclosedf ie ld , everyht(X ) be ingcomplete ly
rmalformcorrespondingtoeachinvariant
ordanformseachcorrespondingtoanelemen-
A . B yashif t ingof therowsandco lumnsthese
anyorder. ThusB (X ) canbechosen
n ( l) + . .. + n { X ) ,
e ordanformcorrespondingtoanelementary
s e ,: ) .
earetw otypesof invariantforthef ie ld ,
haracterist ice uation, X ^ , . . ., X j , w hichmay
tiona latheoriedessystemslinea ires. Z urich190 .
ationtoA . H urw itz.
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nts,andthee ponentseuoftheelementary
edinvariantsofstructure1.The e ponents
e 1
e22, .. . ) ,. . . constitutethe egrecharacterist ic
fmatrices. Twopairso fmatricesA l, A 2
entsinacommutativefie ld% aresa idtobee ui-
e isttwonon-singularmatricesPandQ
that
P B 2 Q .
ndB 1arenon-singular,thefairsof matrices
a r e e u i va l en t i f an d o nl y i f th e ma t ri c es A l X + A 2
hepo lynomia ldomain (X ) havethesameinvariant
sors)3.
A , B 1 a+ B 2 = B . f A l = P B l Q an dA 2 = P B 2 Q ,
Q foreveryX . nthedomainty (X ), PandQ
determinantsarenon-zeronumbersof
ariantfactorsof A andB coincide.
B havethesameinvariantfactors, there
dQ 1whosedeterminantsarenon-zeronumbers
ay invo lveX , suchthatA = P lB Q 1. ince
heree istbyTheorem29.3tw onon-singular
lementsin% suchthat
1 X + B 2 ) Q
n c e A 1 = P B 1 Q a n d A 2 = P B 2 Q .
erebothA landA 2aresingular, it ismore
mmetriclinearcombinationA lX A 2f iw hose
mialdomain^ (X ,fi)ofhomogeneouspoly-
n^ (X , f i) isisomorphicw ith (a). The
X + A 2f iw il lbecalledthe invariantfactors
epairo fmatricesA ^ , A 2issa idtobeanon-
A 2, u)isnotzero in^ (X , f i) .
= A 1 f + A 2 , A 2 = A 1 r + A 2 s , wh er e f, , r, s
a n d A 2 a r e in a n d if f s r = j = 0 , t h e n th e
+ A 2f iareobtainedf romthoseofA 1u+ A 2v
X + s / n .
n . Fa c . c i . Un i v. T o ul o us e V o l . 2 8 (1 9 14 ) p p. 1 8 4 .
c c ad . n az . i n ce i , Me m . l l V o l . 1 9 ( 18 8 4) p p . 12 7 1 4 .
r eu B . A k a d . W i ss . 1 8 8 p p . 31 0 3 3 8.
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athitrust.org/access_
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ninverse,definesanautomorphismof
< J J ( , v )b y wh ic h A l X + A 2 f i o o /4 1m + A 2 v .
ngularpairsofmatricesA l,A 2andB 1,B 2
aree uivalentifandonly if theyhavethesame
t, theyhavethesameinvariantfactors. This
heorem30.1.
ingularpair, theree istsanon-singularmatri
. C h o os e r an d s in a ny w ay s o th at p s r = j = 0 ,
+ A 2s. Def ineB / , B 2 cogrediently . Thenby the
e t he s a me i n va r ia n t fa c to r s as B 1 , B 2 , s i nc e A l , A 2
actorsasB l, B 2. nthiscasethepa irsA ^ , A 2
va lentbyTheorem30. 1. Thenthepa irsA uA 2
va l en t .
l isnon-singular, thepa irA l, A 2w ithe lements
th e c an o ni c al p a ir , B w h e re
+ B n- ,
matri o f the i- thinvariantfactoro fA l, A 2.
1isnon-singularthepa irA l, A 2w ithe lements
ie ld ise uivalenttothecanonica lpa ir ,
+ + n- ,
tri o f the i- thinvariantfactoro fA l, A 2.
valenceofsingularpairsofmatrices presents
andP.Muth2treatedsingular pairsof
h3treatedthegenera lcase. . . Dic son4
airsare e uivalentbyrationaltransformations
sameinvariantfactorsandthe sameminimal
fnes. TurnbullandA it en5havean
ngularcase.
rethan onevariableisusuallynotfactorable
eierstrasselementarydivisortheorydoes
applicabletotheproblemof thee uivalence
matrices. . antor genera lizedtheconcept
eometricmethodstohandlethis problem.
uivalenceofpairsofmatriceswas developed
n7. F irstsupposethatl1, .. . , A aretheroots
V o l. 38(1891)pp. 24 49.
o l. 42(1893)pp. 257-272.
nwendungender lementarteiler.Teubner1899.
a ns . A m e r . Ma t h. o c . V o l .2 9 ( 19 2 7) p p . 23 9 2 5 3.
: C anonicalmatrices, C hap. X . Glasgow 1932.
: . -B . B a ye r. A k a d. W i ss . V o l. 98 ( 18 97 ) pp . 3 7 3 81 .
G . D .: T r an s . A m e r. M at h . o c . V o l . 2 ( 1 92 4 ) pp . 4 51 4 7 8.
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\ = 0 a n d ar e a ll d i st i nc t . e t A = ( a r, ) ,B = ( b r l) . T he r e
, . . . , n ), (yn, .. . , y ln), nooneofwhichconsists
= 0 , (i , = i , 2, .. ., n)
0. ( , / = 1 ,2 , )
lizedsothat Z i,iy ibi X i = 1. ince
= h 2 yn bi j k = h 21 yn bu a ,
,
0 , > - < > ^ t = 0.
#re)and = (yrs) areorthogonalrelativetoA andB .
= l l, l2 ,. .. ,X n .
X B \ = 0 a r e no t a ll d i st i nc t , va r io u s
ismultiple , thenumberof linearly independentpo les
e ua ltothemultiplicity . nthiscasethe
ore.Thecasewhenthereare fewerlinearly
emultiplicitypis calledtheirregularcase.
uations
^ ? ( h = 2, .. ., p)
so fX and . fX k isarooto fmultiplicity3.
mberoflinearlyindependentpolesisi, the
X B is
ormations. fPA Q = A , thee lementsof
mmutativefieldg, thematricesPandQ
ctransformationofA withrespecttothe
.
4= 0andMis anarbitrarymatri suchthat
0 t h en
M ) Q = ( A + M )1 (A - M )
nsformationofA .Therearenoothers forwhich
O . 1
Tr a ns . R o y . o c . o n do n V o l . 14 8 ( 18 5 ) p p . 39 4 .
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= ( - A l M) ( + A l M) ,
( A - M ) A 1 ( A + M ).
o feachmemberitfo llow sthat
)1 = ( A + M A { A - M )1 ,
( A + M ( A - M) = A .
e ist, botharenon-singular, andtheydefine
def iningPandQ y ie lds, respective ly ,
, M = A ( - Q )( Q + f .
( P+ ) A ( - Q ),
ree ua l. HenceforeveryPandQ such
( P + ) 1 a nd Q + ) 1 e i s t, t h er e i s an M i n
maybedefinedasin thestatementofthe
andQ + / benon-singularisaserious
asilyavoided.
P A Q = B , d ( Q ) 4 = 0 , t he n f (P ) A f ( Q 1 ) 1 = B ,
ctionsuchthatf(Q 1)isnon-singular.H e
ryand sufficientconditioninorderthatP
nsforminganon-singularmatri intoitselfis
dertheelementarydiv isorsof1 Pand
tcorrespondinge lementarydivisorsareof thesamedegree
aluesof A .
tsinaprincipa lidea lring. fA = PTB P
lementsinaprincipal idealringandif P
congruentw ithB , w rittenA = B . C ongruence
a lence, andisdeterminative, re f le ive , sym-
f . 22. )
x ^^ ofmatri B betransformedbycogre-
matri P intoaformofmatri A , then
epurposeof thew ritertopresentthesub ectas
mthe notionofbilinearform,butthe
yin translatingtheresultsintotheno-
sodesires.ThusTheorem34.1statesthat
ng e w. M a th . V o l . 4 ( 1 87 8 ) pp . 1 3 .
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sin J 5(Theorem21.1). ThenPTQP isof the
property that 12= j = 0anddiv ideseveryother
yelementarytransformationstheseother
s. Theprocessmaybecontinueduntilamatri
eryothere lementof , oranothercongruent
can beobtainedinwhichtheelementin the
rimefactorsthan 12. B yaddingrow 2,
andthenaddingcolumnssimilarly,a new
tainedwhosefirstrowconsistsof
1 2 ^ 23 , ^ 13 = 2 3 ^ 34 , h n = - 1, n
. ., & -1, n)isag.c. d. o f ( l12, . . ., l ln)andcon-
arto f thisproof , acongruentmatri canbe
butwiththeelementin the(1,2mposition
n-1,n). Unless 12 k i^ l, if o revery i, thisg. c.d.
orsthan 12.
stepsamatri canbereachedin
element.B yproceedingsimilarlywiththelast
o lumns, amatri isobta inedinw hich
g 1 , /,
multipleof row 1torow , 23canbemade0.
vencanbemade0insuccession. Thisprovesthe
issingularifnisodd(Theorem8. ). et
ersA ,,h1,h2,h2,. ..,h^ ,ofthecanonical
antfactorsofQ .
eterminantsare^ h ih ,... h .,where
eroftheset1, 2,...,fi nointegerofwhich
e. tisevidentthenthat theg.c.d.ofthe
antsisdt hlh1h2h2h3. . . to ifactors. Thus
, d d 2 = . h 2, , w h i c h pr o ve s t he t h eo r em 1.
ew canonica lformisuni uee ceptthatthe
byassociates.
einvariants( 27).
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athitrust.org/access_
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ewmatriceswithelementsinarecongruent
sameinvariantfactors.
os ew matricesw ithe lementsinaree uivalent,
ew matri the2i-thinvariantfactorise ua l
.
d.oftheminorsof thesameevenorderof
er f ec t s u a re 3 .
achotherconstitutea class.
isbut afinitenumberofclassesof non-singular
endeterminant.
primesinaprincipa lidealringisuni ue
ereis butafinitenumberof choicesforeach
mmetricmatricesisby nomeansas
matrices.Thistheoryoccursin theliterature
w ith uadraticforms. There lationA PTB P
isenste in4, w honotedthatifa uadraticform
ormedbyatransformationofmatri P , thenew
tri A .
mmetricmatri ofran withelements
iscongruentw ithamatri o f theform
Q .
ticalwith thatofthefirst partofthe
ni ue,andindeedtheproblemof finding
nonicalformisoneofe tremedif f iculty if it
thasnotbeen attainedevenfortwo-rowed
arerationalintegers,aswillappearin thene t
ntegralelements.Thistopic,which
ortantchapterin thetheoryofnumbers,
ere. C ompletereferencesuptothedate
eninarticlesby . T . V ahlen , and
ngew . Math. V o l. 8 (1879)pp. 14 208.
nius:1.c.
r e in e a ng e w. M at h . V o l .3 5 ( 18 4 7) p p . 11 7 1 3 .
z y l . m at h . W i ss . V o l . 2 C 2 ( 1 9 04 ) p p. 5 8 2 6 3 8 .
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athitrust.org/access_
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7/28/2019 Thoery of Matrices Mac Duffee
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treatisesbyP. B achmann2andDic son3cover
hy .
altheoremwasstatedbyC .H ermite4and
ouff5.
ta finitenumberofclassesofsymmetric
gralelementsofgivennon-zerodeterminant.
)
clusionhere.
ivedef inite . f
a ,
a , t he m at r i A i s c al l ed r e du c ed . v e ry p o si t iv e
oforder2is congruentwithoneandonly
ca lledindef inite. f / isthatrooto f
0
eradical,ands istheotherroot,then A is
s > 1 , f s < 0 . H e r e a ga i n th e re i s a t le a st o n e
s,and usuallymorethanone,butnever
yamethodofGauss thesecanbear-
edforms sothateachchaincorresponds
ttoindicate thegeneralsituation.C an-
finedinvariouswaysso thateveryclass
stonce andatmosta finitenumberoftimes.
uecanonicalformhasbeenattainedon