cosmologia-5 - istituto nazionale di fisica nuclearebartolo/course_cosmology_early_universe... ·...

LastscaOeringsurface:CMBphotonsdecoupleatrecombina8onepochz~1100(tr~380,000years)LightcouldhavetravelledL~ctr(horizon)Suchadistancewouldsubtendanangleofabout1degree.WeactuallyseeCMBphotonswithnearlythesameTatbiggerangularscales>7°(e.g.COBEsatellite)

>7°

2causallydisconnectedregionsatrecombina8on

THEHORIZONPROBLEM

AdaptedfromhOp://benasque.org/2011Astrophysics/talks_contr/172_Lewis.pdf

η

Χ

ηlastscaOering

A B

ηsingularity

PastlightconeofA PastlightconeofB

AandBnevercommunicatedwitheachother

StandardCosmology(FRW)

η

Χ

ηlastscaOering

A B

ηrehea8ng

PastlightconeofA PastlightconeofB

Infla8onaryCosmology

CommonpastofAandBηsingularity

INFLATION

Ahugeexpansion

Takearegionofsizeatthebeginningofinfla8on:Since,itgetsinflatedby!!!!

8 THE AUTHOR

(100) h =2⇤⇤

H

mPl

(101)⇤

H ⇥ V (⌅)1/4

(102) �⌅ =

(103) ⇥H = 1/Hinfl

(104) ⇥H ⇥ a(t)

number of e-foldingsN = ln(af/ai) =� tf

ti

Hdt � 60(105)

(105)

8 THE AUTHOR

(100) h =2⇤⇤

H

mPl

(101)⇤

H ⇥ V (⌅)1/4

(102) �⌅ =

(103) ⇥H = 1/Hinfl

(104) ⇥H ⇥ a(t)

number of e-foldingsN = ln(af/ai) =� tf

ti

Hdt � 60(105)

(105)

BRIEF ARTICLE 9

(114) ⇥⇧ =

(115) ⌅H = 1/Hinfl

(116) ⌅H ⇧ a(t)

(117) number of e-foldingsN = ln(af/ai) =⇤ tf

ti

Hdt ⇥ 60

(118)af

ai⌅ e60 ⌅ 1026

(119) gij = ⇥ij + hij , hii = ⌥ihij = 0

(120) L[⇧] = L2 + L3 + ...

(121)�T

T⌅ 1

3⇥ = �1

5⇤ ⇤ 10�5

(122) ⌅phys ⇧ a(t)

(123) ⌃⇥⌃k1⇥⌃⇥k2⌥

(124) X = �12gµ�⇧,µ ⇧,� , f(⇧) = ⌅/⇧4

(125) fDBINL = �(35/108)

�1c2s� 1

⇥, cs ⌅ 3/(�N)

(126) ns � 1 = �4/N

(127) ns � 1 = 0.9603± 0.0073

f equilNL = �42± 75 (68%CL)(128)

forthoNL = �26± 39 (68%CL)

BRIEF ARTICLE 9

(114) ⇥⇧ =

(115) ⌅H = 1/Hinfl

(116) ⌅H ⇧ a(t)

(117) number of e-foldingsN = ln(af/ai) =⇤ tf

ti

Hdt ⇥ 60

(118)af

ai⇥ e60 ⌅ 1026

(119) gij = ⇥ij + hij , hii = ⌥ihij = 0

(120) L[⇧] = L2 + L3 + ...

(121)�T

T⌅ 1

3⇥ = �1

5⇤ ⇤ 10�5

(122) ⌅phys ⇧ a(t)

(123) ⌃⇥⌃k1⇥⌃⇥k2⌥

(124) X = �12gµ�⇧,µ ⇧,� , f(⇧) = ⌅/⇧4

(125) fDBINL = �(35/108)

�1c2s� 1

⇥, cs ⌅ 3/(�N)

(126) ns � 1 = �4/N

(127) ns � 1 = 0.9603± 0.0073

f equilNL = �42± 75 (68%CL)(128)

forthoNL = �26± 39 (68%CL)

FromS.Dodelson``ModernCosmology’’,AcademicPress(2003)