The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the large-scale two-point correlation function

ARIEL G. SANCHEZ, ; C. G. SCOCCOLA,; A. J. ROSS, ET AL.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 425 p. 415 - 437

0035-8711

We obtain constraints on cosmological parameters from the spherically averaged redshift space correlation function of the CMASS Data Release 9 (DR9) sample of the Baryonic Oscillation Spectroscopic Survey (BOSS). We combine this information with additional data from recent cosmic microwave background (CMB), supernova and baryon acoustic oscillation measurements. Our results show no significant evidence of deviations from the standard flat LAMBDA cold dark matter model, whose basic parameters can be specified by omega_m = 0.285 pm 0.009, 100omega_b = 4.59 pm 0.09, ns = 0.961 pm 0.009, H0 = 69.4 pm 0.8 km/s /Mpc and sigma_8 = 0.80 pm 0.02. The CMB+CMASS combination sets tight constraints on the curvature of the Universe, with omega_k =-0.0043 pm 0.0049, and the tensor-to-scalar amplitude ratio, for which we find r < 0.16 at the 95 per cent confidence level (CL). These data show a clear signature of a deviation from scale invariance also in the presence of tensor modes, with ns < 1 at the 99.7 per cent CL. We derive constraints on the fraction of massive neutrinos of f_nu < 0.049 (95 per cent CL), implying a limit of Sum m_nu < 0.51 eV. We find no signature of a deviation from a cosmological constant from the combination of all data sets, with a constraint of w_DE = -1.033 pm 0.073 when this parameter is assumed time-independent, and no evidence of a departure from this value when it is allowed to evolve as w_DE(a) = w0 + wa(1-a). The achieved accuracy on our cosmological constraints is a clear demonstration of the constraining power of current cosmological observations.