PROBING FOR THE COSMOLOGICAL PARAMETERS WITH PLANCK MEASUREMENT

摘要

In this paper we investigate the constraints on the cosmological parameters, especially the equation of state of dynamical dark energy omega(DE), the inflationary parameters n(s), alpha(s) and r, the total neutrino mass Sigma m(v) and the curvature of the universe Omega(K), using the simulated data of future Planck measurement. First, we determine the cosmological parameters with the current observations, including ESSENCE (192 samples), Three- Year WMAP (WMAP3), Boomerang-2K2, CBI, VSA, ACBAR, SDSS LRG and 2dFGRS, and then we take the best-fit model as the fiducial model in the ensuing simulations. In the simulations we pay particular attention to the effects of the dynamical dark energy in the determination of the cosmological parameters. For this reason, in order to make our constraints more robust, we have added the simulated SNAP data to our simulations. Using the present data, we find that the Quintom dark energy model is mildly favored, while the Lambda CDM model remains a good fit. In the framework of the dynamical dark energy model, the constraints on the inflationary parameters, Sigma m(v) and Omega(K), become weak, compared with the constraints in the Lambda CDM model. Intriguingly, we find that the inflationary models with a "blue" tilt, which are excluded about 2 sigma in the Lambda CDM model, are well within the 2 sigma region with the presence of the dynamics of dark energy. The upper limits of neutrino mass are weakened by a factor of 2 (95% CL) - say, Sigma m(v) < 1.59 eV and Sigma m(v) < 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 Omega(K) < 0.03 (95% CL). With the simulated Planck and SNAP data, the dynamical dark energy model and the Lambda CDM model might be distinguished at the 4 sigma confidence level. And the uncertainties of the inflationary parameters, Sigma m(v) and Omega(K), can be reduced significantly in the framework of the dynamical dark energy model. We also constrain the rotation angle Delta alpha, denoting the possible CPT violation, from the simulated Planckand CMBpol data and find that our results are much more stringent than the current constraint and will be used to verify the CPT symmetry with a higher precision.