Probing for the Cosmological Parameters with PLANCK Measurement

Abstract

We investigate the constraints on cosmological parameters especially for EoS of dark energy, inflationary parameters, neutrino mass and curvature of universe using simulated Planck data. Firstly we determine cosmological parameters with current observations including ESSENCE, WMAP3, Boomerang-2K2, CBI, VSA, ACBAR, SDSS LRG and 2dFGRS, and take best-fit model as the fiducial model in simulations. In simulations we pay attention to the effects of dynamical dark energy in determination of cosmological parameters. We add simulated SNAP data to do all the simulations. Using present data, we find Quintom dark energy model is mildly favored while \LambdaCDM remains a good fit. In the framework of dynamical dark energy, the constraints on inflationary parameters, m_ν and Ω_{K} become weak compared with the constraints in \LambdaCDM. Intriguingly, we find that the inflationary models with a "blue" tilt, which are excluded about 2σin \LambdaCDM model, are well within 2σregion with the presence of the dynamics of dark energy. The upper limits of neutrino mass are weakened by a factor of 2 (95% C.L.), say, m_ν<1.59 eV and m_ν<1.53 eV for two forms of parametrization of the equation of state of dark energy. The flat universe is a good fit to the current data, namely, |Ω_{K}|<0.03 (95% C.L.). With the simulated Planck and SNAP data, dynamical dark energy and \LambdaCDM might be distinguished at 4σ. And uncertainties of inflationary parameters, m_ν and Ω_{K} can be reduced obviously. We also constrain the rotation angle Δα, denoting possible cosmological CPT violation, with simulated Planck and CMBpol data and find that our results are much more stringent than current constraint and will verify cosmological CPT symmetry with a higher precision. (Abridged)