Constraining Cosmological Parameters with Observational Data Including Weak Lensing Effects

TL;DR

This study combines multiple observational datasets, including weak lensing, CMB, galaxy surveys, and supernovae, to constrain cosmological parameters, confirming the DM model and exploring dark energy, neutrino mass, and inflation constraints.

Contribution

It is the first comprehensive analysis integrating weak lensing data with other cosmological observations to refine parameter constraints and examine dark energy dynamics.

Findings

Weak lensing data improve constraints on DM parameters.

Upper limit on total neutrino mass is < 0.471 eV.

Inflation models with n_s e2 1 are excluded at > 2 b1 confidence.

Abstract

In this paper, we study the cosmological implications of the 100 square degree Weak Lensing survey (the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys). We combine these weak lensing data with the cosmic microwave background (CMB) measurements from the WMAP5, BOOMERanG, CBI, VSA, ACBAR, the SDSS LRG matter power spectrum and the Type Ia Supernoave (SNIa) data with the "Union" compilation (307 sample), using the Markov Chain Monte Carlo method to determine the cosmological parameters. Our results show that the \Lambda CDM model remains a good fit to all of these data. For the dynamical dark energy model with time evolving EoS parameterized as w_{\DE}(a) = w_0 + w_a (1-a), we find that the best-fit model implying the mildly preference of Quintom model whose EoS gets across the cosmological constant boundary during evolution. Regarding the total neutrino mass limit, we obtain the upper limit, \sum m_{\nu}< 0.471 eV (95% C.L.) within the framework of the flat \Lambda CDM model. Due to the obvious degeneracies between the neutrino mass and the EoS of dark energy model, this upper limit will be relaxed by a factor of 2 in the framework of dynamical dark energy models. For the constraints on the inflation parameters, we find that the upper limit on the ratio of the tensor to scalar is r<0.35 (95% C.L.) and the inflationary models with the slope n_s\geq1 are excluded at more than 2 \sigma confidence level. In this paper we pay particular attention to the contribution from the weak lensing data and find that the current weak lensing data do improve the constraints on matter density \Omega_m, \sigma_8, \sum{m_{\nu}}, and the EoS of dark energy.