SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE ( WMAP ) OBSERVATIONS: SKY MAPS, SYSTEMATIC ERRORS, AND BASIC RESULTS

Abstract

New full sky temperature and polarization maps based on seven years of data from WMAP are presented. The new results are consistent with previous results, but have improved due to reduced noise from the additional integration time, improved knowledge of the instrument performance, and improved data analysis procedures. The improvements are described in detail.The seven year data set is well fit by a minimal six-parameter flat ΛCDM model. The parameters for this model, using the WMAP data in conjunction with baryon acoustic oscillation data from the Sloan Digital Sky Survey and priors on H 0 from Hubble Space Telescope observations, are: Ω b h 2 = 0.02260 ± 0.00053, Ω c h 2 = 0.1123 ± 0.0035, Ω Λ = 0.728 +0.015 −0.016 , n s = 0.963 ± 0.012, τ = 0.087 ± 0.014 and σ 8 = 0.809 ± 0.024 (68 % CL uncertainties).The temperature power spectrum signal-to-noise ratio per multipole is greater that unity for multipoles ℓ 919, allowing a robust measurement of the third acoustic peak. This measurement results in improved constraints on the matter density, Ω m h 2 = 0.1334 +0.0056 −0.0055 , and the epoch of matter-radiation equality, z eq = 3196 +134 −133 , using WMAP data alone. The new WMAP data, when combined with smaller angular scale microwave background anisotropy data, results in a 3σ detection of the abundance of primordial Helium, Y He = 0.326 ± 0.075. When combined with additional external data sets, the WMAP data also yield better determinations of the total mass of neutrinos, m ν =< 0.58 eV (95% CL), and the effective number of neutrino species, N eff = 4.34 +0.86 −0.88 . The power-law index of the primordial power spectrum is now determined to be n s = 0.963 ± 0.012, excluding the Harrison-Zel'dovich-Peebles spectrum by > 3σThese new WMAP measurements provide important tests of Big Bang cosmology.

Observational probes of cosmic acceleration

“…Both the matter-to-radiation ratio and the baryon-to-photon ratio are well measured by the relative heights of the acoustic peaks in the CMB anisotropy power spectrum. Analyses of WMAP data in the usual ΛCDM cosmological models gives a 1.1% inference of the acoustic scale r s (Jarosik et al, 2011); Planck is expected to shrink this error bar to 0.25%. Note that the acoustic scale is determined in absolute units, Mpc not h −1 Mpc.…”

Confusing the extragalactic neutrino flux limit with a neutrino propagation limit

“…Considering, for instance, λ = L/3 ∼ 33 Mpc, we can compute the cross section σ as a function of the DM particle's mass m DM . We consider for the mean DM density in the universe, ρ DM = 1.2 × 10 −6 GeV/cm 3 [13]. In figure 2 we show the space of parameters that results in a 95% neutrino flux suppression or more.…”

“…Cosmological observations of clusters of galaxies indicate that the density fraction of DM is Ω DM ≈ 0.227 ± 0.014 [13]. The two most popular solution to the DM problem are i) a slight modification on the Newtonian dynamics [14] and ii) relic particles [15].…”

Analytic rotating black-hole solutions in N-dimensional f(T) gravity

“…The accelerated expansion of our Universe is confirmed by many separated cosmological experiments [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. This expansion can be explained in GR by taking into account the dark energy component in the total energy of our Universe.…”