WMAP-2006: Cosmological parameters and large-scale structure of the universe

Abstract

The parameters of the cosmological model with cold dark matter and cosmological constant (ΛCDM model) were determined using three-year Wilkinson Microwave Anisotropy Probe observations of cosmic microwave background together with some data on the large-scale structure of the universe. The data cover scales from 1 to 10 000 Mpc. The best-fit ΛCDM model parameters were derived by minimizing the x 2 statistic with the use of the Levenberg-Markquardt approach (ΩΛ = 0.736 ± 0.065, Ωm = 0.238 ± 0.080, Ωb = 0.05 ± 0.011, h = 0.68 ± 0.09, σ8 = 0.73 ± 0.08, and n s = 0.96 ± 0.015). The ΛCDM model with these parameters is shown to agree well with the angular power spectrum of cosmic microwave background temperature fluctuations and with the density perturbation power spectra estimated from spatial distributions of galaxies and rich clusters of galaxies as well as from the statistics of the Ly α absorption lines in the spectra of distant quasars. The accord between the model large-scale structure characteristics and the observed ones is analyzed, and conceivable factors causing appreciable discrepancies between some characteristics are discussed.