yanchuan cai ( 蔡彦川 ) shaun cole, adrian jenkins, carlos frenk institute for computational...
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Yanchuan Cai ( 蔡彦川 )
Shaun Cole, Adrian Jenkins, Carlos Frenk
Institute for Computational Cosmology
Durham University
May 31, 2008, NDHU, Taiwan
ISW Cross-Correlation
Potential decay – ISW effect
Linear regime – Integrated Sachs-Wolfe effect (ISW) (Sachs & Wolfe 1967)
Non-linear regime - Rees-Sciama effect (RS) (Rees & Sciama 1968)
ISW & RS effect capture the dynamics of the universe
Potential change induce secondary CMB temperature fluctuation
Constraint of Dark energy
In a flat universe: 0, 1 0, 0
0 0, 0
linm
lin
If P
If P
( / ) /d D a dt
Imprint on the CMB Power spectrum
Cooray 2002 Hu 2001The ISW effect is difficult to be detected from the CMB power spectrum due to cosmic variance.The Rees-Sciama effect is negligible for the CMB PS, but…
Cross-correlation of LSS & CMB
( / ) /d D a dz
N(z)
ISW fluctuations are correlated with galaxy distributionGalaxies are bias tracer to large scale structure
b(t): Galaxy bias parameterN(t): Galaxy selection function
Sky covrerage: 5.5×5.5 deg2, Survey Depth: mean z~0.15
APM-WMAP cross-correlation
Fosalba & Gaztanag 2004;
SZ
ISW
Galaxy survey with CMB map
Cabre et al. 2006
ISW Tomography – Dark Energy Evolution
LSST
Pan-STARRS
Cai et al. in preparation; Hu & Scranton 2004; LoVerde et al. 2007
Deep galaxy survey: detection of the evolution of dark energyLarge sky coverage: improving S/N
ISW + Rees-Sciama + SZ + Lensing + Doppler redshift + …
You may expect more than ISW…
WMAP sees hereWMAP sees here
Sunyaev-Zel’dovich effect
Doppler effectLensing magnification
LOS
tSZ
Moving halo effect
ISW+Dop+LenISW+Dop
ISW
Seljak 1995; Afshordi et al. 2004; Fosalba & Gaztanag 2004; LoVerde et al. 2007
Rees-Sciama effect SZ effect
Power spectra of thepotential derivative measured from the
L-BASICC simulation.
The second order contribution can be
well modeled by a broken power law.
Deviation of the total power spectrum
from linear theory occurs at larger
scales as redshift Increase.
ISW ISW
Cai et al. in prep.
ISW + RSISW + RS
Cai et al. in prep.
2-D Power spectra of the potential derivative measured from the L-BASICC simulation.
L-BASICC simulation is the LambdaCDMcosmology with
Deviation of the total power spectrum from linear theory occurs at larger scales as redshift increase.
ISW ISW
ISW + RSISW + RS
8
0.75, 25,
0.024, 0.9
m
b
Cai et al. in prep.
ISW + RSISW + RS
ISWISW
ISW cross-correlation
Cai et al. in prep.
ISW + RSISW + RS
ISWISW
ISW cross-correlation
Summary Cross-correlation of LSS & CMB provides co
nstraint to dark energy ISW tomography is promising, but hard Separating ISW, SZ, lensing magnification,
Doppler effect, Rees-Sciama effect… RS effect dominates at high-z, could be imp
ortant on the scale of a few degrees Accurate modeling of the RS effect would b
e useful