Constraints on dark energy parameters from correlations of CMB with LSS

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 ΛCDM model, we find that the ISW data, as a complement to the WMAP data, could significantly improve the constraint of curvature Ωk. 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 Ωk 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) = w0+wa(1−a), we find that the ΛCDM model remains a good fit to the current data. When taking into account the ISW data, the error bars of w0 and wa could be shrunk slightly. Current constraints on the dynamical dark energy model are not conclusive. The future precision measurements are needed