南京大学物理学院：暗能量扰动（PPT讲稿）Dark Energy Perturbations

Dark Energy Perturbations 李明哲 南京大学物理学院 20111013中国科技大学交叉学科理论研究中心合肥

Dark Energy Perturbations 李明哲 南京大学物理学院 2011.10.13 中国科技大学交叉学科理论研究中心 合肥

Outline Importance of cosmological perturbations Dark energy models Dark energy perturbations Dark energy coupling to CMB photons I Dark energy coupling to CMB photons Conclusions

Outline • Importance of cosmological perturbations • Dark energy models • Dark energy perturbations • Dark energy coupling to CMB photons I • Dark energy coupling to CMB photons II • Conclusions

Importance of cosmological perturbations DAWN TIME inflation tiny fraction of a second 380,000 years years

Importance of cosmological perturbations

Inflation quantum fluctuation Primordial perturbation r, v,p, n, e, dm

Inflation quantum fluctuation Primordial perturbation , , , , ,dm...    p n e

1965 CMB anisotropy COBE A WMAP

1965 COBE WMAP CMB anisotropy

CMB Angular power spectrum 6000 TT 5000 4000 3000 ±200 00 TE FT 100 500 1000 Multipole moment I ests of perturbation theory

Tests of perturbation theory CMB Angular Power Spectrum

Matter power spectrum Wavelengthλ[h-1Mpc] 104 1000 100 10 10 104 a1000 100 Cosmic Microwave Background ● SDSS galaxies ☆ Cluster abundance 10 a Weak lensing ▲ Lyman Alpha Forest il 0.001 0.01 0.1 10 Wavenumber k [h/Mpc]

Matter Power Spectrum

Dark Energy(DE) Supernova Cosmology Project 3" Big Bang 2 Supernovae q(z=0+z(dg/dz Constant Acceleration. o daldzE 0100 6E 〓〓二 二二二9=一二 749% Dark Energy Coasting, q z) Constant Deceleration.=+.dg/dz:0. 1:01 229 Dark Acceleration+ Deceleration dz=++ Matter 4% Ato

Dark Energy (DE)

H 2 87G Accelerating universe a/ a 4(+3p)>0 Negative pressure W三 <-1/3 Cosmological Constant(Einstein 1917) Rour+ Aguy=-87GTHv v 8G(T+ v 8zg A A A UV(A) dIG v 87G guv=p No perturbation

1/ 3 / ( 3 ) 0 3 4 3 2 8 =  − = − +  =      p w a a p H G G  Accelerating universe Negative pressure R  Rg   g  8G T  2 1 − +  = − ) 8 8 ( 2 1           g G R Rg G T  − = − +      g G T 8 ( )   =  = −   = g p G     8 w = −1 1, Cosmological Constant (Einstein 1917) No perturbation

Cosmological constant problem Observation P≈(2×10eV 4 Zero point energy density kvk+m M dk 4兀 16丌 M=Mn-10°eV,,~102p

3 4 (2 10 eV) −     Cosmological constant problem Observation Zero point energy density   + = M v M dk k k m 0 2 4 2 2 2 2 4 16  =   28 121 M Mpl ~10 eV, v ~10