Cosmological parameters from complementary observations of the Universe

Abstract

We use observational data on the large scale structure (LSS) of the Universe measured over a wide range of scales from sub-galactic up to horizon scale and on the cosmic microwave background anisotropies to determine cosmological parameters within the class of adiabatic inflationary models. We show that a mixed dark matter model with cosmological constant ($Λ$MDM model) and parameters $Ω_m=0.37^{+0.25}_{-0.15}$, $Ω_Λ=0.69^{+0.15}_{-0.20}$, $Ω_ν=0.03^{+0.07}_{-0.03}$, $N_ν=1$, $Ω_b=0.037^{+0.033}_{-0.018}$, $n_s=1.02^{+0.09}_{-0.10}$, $h=0.71^{+0.22}_{-0.19}$, $b_{cl}=2.4^{+0.7}_{-0.7}$ (1$σ$ confidence limits) matches observational data on LSS, the nucleosynthesis constraint, direct measurements of Hubble constant, the high redshift supernova type Ia results and the recent measurements of the location and amplitude of the first acoustic peak in the CMB anisotropy power spectrum. The best model is $Λ$ dominated (65% of the total energy density) and has slightly positive curvature, $Ω=1.06$. The clustered matter consists in 8% massive neutrinos, 10% baryons and 82% cold dark matter (CDM). The upper 2$σ$ limit on the neutrino content can be expressed in the form $Ω_νh^2/N_ν^{0.64}\le0.042$ or, via the neutrino mass, $m_ν\le4.0$eV. The upper 1(2)$σ$ limit for the contribution of a tensor mode to the COBE DMR data is T/S$<1(1.5)$. Furthermore, it is shown that the LSS observations together with the Boomerang (+MAXIMA-1) data on the first acoustic peak rule out zero-$Λ$ models at more than $2σ$ confidence limit.