Constraining cosmological parameters with observational data including weak lensing effects

In this Letter 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 la Supernoave (SNla) data with the Union compilation (307 sample), using the Markov Chain Monte Carlo method to determine the cosmological parameters, such as the equation-of-state (EoS) of dark energy w, the density fluctuation amplitude sigma(8), the total neutrino mass Sigma m(v), and the parameters associated with the power spectrum of the primordial fluctuations. Our results show that the Lambda CDM model remains a good fit to all of these data. In a flat universe, we obtain a tight limit on the constant EoS of dark energy, w = -0.97 +/- 0.041 (1 sigma). 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 values are w(0) = -1.064 and w(a) = 0.375, 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 tipper limit, Sigma m(v) < 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. Assuming that the primordial fluctuations are adiabatic with a power law spectrum, within the Lambda CDM model, 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) >= 1 are excluded at more than 2 sigma confidence level. In this Letter we pay particular attention to the contribution front the weak lensing data and find that the current weak lensing data do improve the constraints on matter density Omega(m), sigma(8), Sigma m(v), and the EoS of dark energy. (C) 2009 Elsevier B.V. All rights reserved.