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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
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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
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Constraint of Dark energy In a flat universe:
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Imprint on the CMB Power spectrum Cooray 2002Hu 2001 The 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…
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Cross-correlation of LSS & CMB N(z) ISW fluctuations are correlated with galaxy distribution Galaxies are bias tracer to large scale structure b(t): Galaxy bias parameter N(t): Galaxy selection function
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Sky covrerage: 5.5×5.5 deg 2, Survey Depth: mean z~0.15 APM-WMAP cross-correlation Fosalba & Gaztanag 2004; SZ ISW Galaxy survey with CMB map
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Cabre et al. 2006
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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 energy Large sky coverage: improving S/N
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ISW + Rees-Sciama + SZ + Lensing + Doppler redshift + … You may expect more than ISW…
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WMAP sees here Sunyaev-Zel’dovich effect Doppler effect Lensing magnification LOS tSZ Moving halo effect
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ISW+Dop+Len ISW+Dop ISW Seljak 1995; Afshordi et al. 2004; Fosalba & Gaztanag 2004; LoVerde et al. 2007 Rees-Sciama effect SZ effect
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Power spectra of the potential 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 Cai et al. in prep. ISW + RS
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Cai et al. in prep. 2-D Power spectra of the potential derivative measured from the L-BASICC simulation. L-BASICC simulation is the LambdaCDM cosmology with Deviation of the total power spectrum from linear theory occurs at larger scales as redshift increase.ISW ISW + RS
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Cai et al. in prep. ISW + RS ISW ISW cross- correlation
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Cai et al. in prep. ISW + RS ISW ISW cross- correlation
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Summary Cross-correlation of LSS & CMB provides constraint 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 important on the scale of a few degrees Accurate modeling of the RS effect would be useful
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