Limits of dark energy measurements from CMB lensing-ISW-galaxy count correlations

Abstract

I discuss several issues that arise when trying to constrain the dark energy equation of state using correlations of the integrated Sachs-Wolfe effect with galaxy counts and lensing of the cosmic microwave background. These techniques are complementary to others such as galaxy shear surveys, and can use data that will already be obtained from currently planned observations. In regimes where cosmic variance and shot noise are the dominant sources of error, constraints could be made on the mean equation of state to within 0.33 and its first derivative to within 1.0. Perhaps more interesting is that the determination of dark energy parameters by these types of experiments depends strongly on the presence or absence of perturbations in the dark energy fluid.

6 pages, 5 figures. Accepted by PRD, changes to fiducial model and other model details, errors in figures 4 and 5 fixed, references added

Cited by in corpus (8)

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• Cosmic Growth History and Expansion History
• Cosmology with Weak Lensing Surveys
• Observational constraints on low redshift evolution of dark energy: How consistent are different observations?
• The shape of the CMB lensing bispectrum
• Dark energy records in lensed cosmic microwave background
• Parametrised modified gravity and the CMB Bispectrum
• Cosmic microwave background constraints on dark energy dynamics: analysis beyond the power spectrum