Probing for the Cosmological Parameters with PLANCK Measurement

TL;DR

This paper uses simulated Planck data to explore how well cosmological parameters, including dark energy, inflation, neutrino mass, and curvature, can be constrained, highlighting the potential to distinguish models and test fundamental symmetries.

Contribution

It demonstrates the improved constraints on cosmological parameters achievable with future Planck and SNAP data, especially for dynamical dark energy and CPT violation.

Findings

Quintom dark energy mildly favored over mbdaCDM.

Constraints on inflationary tilt are relaxed in dynamical dark energy models.

Neutrino mass upper limits are weakened, and universe curvature remains tightly constrained.

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_{\nu} and \Omega_{K} become weak compared with the constraints in \LambdaCDM. Intriguingly, we find that the inflationary models with a "blue" tilt, which are excluded about 2\sigma in \LambdaCDM model, are well within 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% C.L.), say, m_{\nu}<1.59 eV and m_{\nu}<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% C.L.). With the simulated Planck and SNAP data, dynamical dark energy and \LambdaCDM might be distinguished at 4\sigma. And uncertainties of inflationary parameters, m_{\nu} and \Omega_{K} can be reduced obviously. We also constrain the rotation angle \Delta\alpha, 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)