Constraints on Dark Energy Parameters from Correlations of CMB with LSS

TL;DR

This paper combines multiple observational datasets, including CMB, BAO, SN, and ISW data, to constrain dark energy parameters, finding that ISW data improves curvature constraints and that current data favor a cosmological constant.

Contribution

It provides new constraints on dark energy parameters by integrating ISW data and a new Hubble constant prior, enhancing curvature and dark energy equation of state estimates.

Findings

ISW data improves curvature  constraints.

New Hubble prior halves the uncertainty in .

Current data are consistent with a cosmological constant.

Abstract

In this paper, we combine the the latest observational data, including the WMAP five-year data (WMAP5), the baryon acoustic oscillations (BAO) and type Ia supernovae (SN) "union" compilation, and use the Markov Chain Monte Carlo method to determine the dark energy parameters. We pay particular attention to the Integrated Sache-Wolfe (ISW) data from the cross-correlations of cosmic microwave background (CMB) and large scale structure (LSS). In the \Lambda CDM model, we find that the ISW data, as a complement to the WMAP data, could significantly improve the constraint of curvature \Omega_k. We also check the improvement of constraints from the new prior on the Hubble constant and find this new prior could improve the constraint of \Omega_k by a factor of 2. Finally, we study the dynamical evolving EoS of dark energy from the current observational data. Based on the dynamical dark energy model, parameterizing as w(a)=w_0+w_a(1-a), we find that the \Lambda CDM model remains a good fit to the current data. When taking into account the ISW data, the error bars of w_0 and w_a could be shrunk slightly. Current constraints on the dynamical dark energy model are not conclusive. The future precision measurements are needed.