The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measuring DA and H at z = 0.57 from the baryon acoustic peak in the Data Release 9 spectroscopic Galaxy sample

Abstract

We present measurements of the angular diameter distance to and Hubble parameter at z = 0.57 from the measurement of the baryon acoustic peak in the correlation of galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey. Our analysis is based on a sample from Data Release 9 of 264,283 galaxies over 3275 square degrees in the redshift range 0.43 < z < 0.70. We use two different methods to provide robust measurement of the acoustic peak position across and along the line of sight in order to measure the cosmological distance scale. We find D A (0.57) = 1408 ± 45 Mpc and H(0.57) = 92.9 ± 7.8 km/s/Mpc for our fiducial value of the sound horizon. These results from the anisotropic fitting are fully consistent with the analysis of the spherically averaged acoustic peak position presented in Anderson et al. (2012). Our distance measurements are a close match to the predictions of the standard cosmological model featuring a cosmological constant and zero spatial curvature.

AIC, BIC, Bayesian evidence against the interacting dark energy model

“…We used the observational data of 580 type Ia supernovae (the Union2.1 compilation [56]), 31 observational data points of the Hubble function from [57][58][59][60][61][62][63][64][65][66] collected in [67], the measurements of BAO from the Sloan Digital Sky Survey (SDSS-III) combined with the 2dF Galaxy Redshift Survey [68][69][70][71], the 6dF Galaxy Survey [72,73], and the WiggleZ Dark Energy Survey [74][75][76]. We also used information coming from determinations of the Hubble function using the Alcock-Paczyński test [77,78].…”

A Possible Alternative to the Accelerating Universe III

“…In two previous works by the author [1] [2], hereafter referred to as I and II, it was shown that it is possible to explain the diminished brightness of the Type Ia supernovae (SNe Ia) found by Perlmutter et al [3] [4], Riess et al [5], and Schmidt et al [6], and the increased distance to the "standard ruler" of the baryon acoustic oscillations (BAO) determined by Anderson et al [7] [8], by assuming that the speed of light through the dark energy of intergalactic space has been reduced to c/n, where n is the index of refraction of the dark energy. Thus, in this alternative model, the dark energy no longer has associated with its energy-momentum source tensor a negative pressure that causes the expansion of the universe to accelerate (for a review see, e.g., Wang [9]), but instead has an index of refraction greater than unity.…”

MODEL-INDEPENDENT DETERMINATION OF CURVATURE PARAMETER USING H ( z ) AND D A ( z ) DATA PAIRS FROM BAO MEASUREMENTS

“…Since derivations of H (z) and D A (z) pairs from BAO measurements are purely geometrical, Equation (1) can be evaluated without any assumption of dynamic evolution of the universe, and therefore breaks the degeneracy between curvature and the dark energy equation of state. Several works have already derived H (z) and D A (z) pairs from the data of the WiggleZ Dark Energy Survey at z = 0.44, 0.6, 0.73 (Blake et al 2012), and the third generation Sloan Digital Sky Survey (SDSS-III) at z = 0.35 (Chuang & Wang 2012;Hemantha et al 2013;Xu et al 2013) and z = 0.57 (Reid et al 2012;Kazin et al 2013;Chuang et al 2013;Anderson et al 2014;Samushia et al 2014). With the quasar-Lyman α forest in SDSS-III, measurements of H (z) and D A (z) have extended to high redshifts such as z = 2.36 (Font-Ribera et al 2014).…”