ISW effect as probe of features in the expansion history of the Universe

Abstract

In this paper, using and implementing a new line of sight CMB code, called CMBAns [1], that allows us to modify H(z) for any given feature at any redshift we study the effect of changes in the expansion history of the Universe on the CMB power spectrum. Motivated by the detailed analytical calculations of the effects of the changes in H(z) on ISW plateau and CMB low multipoles, we study two phenomenological parametric form of the expansion history using WMAP data and through MCMC analysis. Our MCMC analysis shows that the standard LCDM cosmological model is consistent with the CMB data allowing the expansion history of the Universe vary around this model at different redshifts. However, our analysis also shows that a decaying dark energy model proposed in [2] has in fact a marginally better fit than the standard cosmological constant model to CMB data. Concordance of our studies here with the previous analysis showing that Baryon Acoustic Oscillation (BAO) and supernovae data (SN Ia) also prefer mildly this decaying dark energy model to LCDM, makes this finding interesting and worth further investigation.

20 pages, 11 figures, 2 tables, discussions extended, references added, results unchanged, matches final version published in JCAP

References in corpus (5)

• Two new diagnostics of dark energy
• Planck 2013 results. XV. CMB power spectra and likelihood
• Cosmological parameter estimation with free-form primordial power spectrum
• New Constraints on the Early Expansion History
• Model Independent Early Expansion History and Dark Energy

Cited by in corpus (7)

• Sources of $H_0$-tensions in dark energy scenarios
• Suppressing CMB low multipoles with ISW effect
• Constraints on a decomposed dark fluid with constant adiabatic sound speed by jointing the geometry test and growth rate after Planck data
• Early dark energy and its interaction with dark matter
• SCoPE: An efficient method of Cosmological Parameter Estimation
• Leakage of power from dipole to higher multipoles due to non-symmetric WMAP beam
• Cosmic Microwave Background Anisotropy numerical solution (CMBAns) I: An introduction to $C_l$ calculation