On using the WMAP distance priors in constraining the time evolving equation of state of dark energy

TL;DR

This paper evaluates the effectiveness of WMAP distance priors in constraining the evolving dark energy equation of state, highlighting the importance of including dark energy perturbations for accurate results.

Contribution

It demonstrates that WMAP distance priors can yield constraints comparable to full CMB data when dark energy perturbations are considered, emphasizing the significance of proper modeling.

Findings

Distance priors provide similar constraints to full CMB data with perturbations included.

Neglecting dark energy perturbations leads to significantly different results.

Proper inclusion of perturbations is crucial for accurate dark energy parameter estimation.

Abstract

Recently, the WMAP group has published their five-year data and considered the constraints on the time evolving equation of state of dark energy for the first time from the WMAP distance information. In this paper, we study the effectiveness of the usage of these distance information and find that these compressed CMB information can give similar constraints on dark energy parameters compared with the full CMB power spectrum if dark energy perturbations are included, however, once incorrectly neglecting the dark energy perturbations, the difference of the results are sizable.