THE INTEGRATED SACHS-WOLFE EFFECT IN CROSS-CORRELATION WITH GALAXY SAMPLES - A RELIABLE INDEPENDENT PROBE FOR CONSTRAINING COSMOLOGY

摘要

The A-dominated Cold Dark Matter (ACDM) model predicts the existence of a secondary anisotropy of the Cosmic Microwave Background (CMB), called Integrated Sachs-Wolfe (ISW) effect, due to the passing of CMB photons, after the radiation-matter decoupling, through regions with time varying gravitational potential. Since the ISW effect is manifesting at large angular scales in the CMB anisotropies, where it is dominated by the primary CMB anisotropies and by the cosmic variance, has been proposed to measure the ISW effect of CMB from the cross-correlation with local tracers of the gravitational potential from Large Scale Structure (LSS) observations. We analyze the ability of this probe to constrain the cosmological model, especially the dark energy component. We found an agreement between the constraint on the dark-energy density parameter, ΩA , from CMB anisotropy-galaxy overdensity cross-correlation data, and that from CMB anisotropy data alone. Though the ISW effect gives a weaker determination of Ω A than CMB anisotropy data, it can be used as an independent test for the dark energy.