Median statistics cosmological parameter values

Abstract

We present median statistics central values and ranges for 12 cosmological parameters, using 582 measurements (published during 1990-2010) collected by Croft & Dailey (2011). On comparing to the recent Planck collaboration Ade et al. 2013 estimates of 11 of these parameters, we find good consistency in nine cases.Comment: 12 pages, 2 figures, 1 tabl

Median Statistics Estimate of the Distance to the Galactic Center

“…The one (two) standard deviation error associated with the median is defined in Gott et al (2001) as the range about the median including 68.27% (95.45%) of the probability. 3 The one standard deviation error given by a Gott et al (2001) 68.27% confidence range is smaller than that obtained by binning the measurements and integrating outwards to 68.27% of the total area around the median (Crandall & Ratra 2014). We call the error determined from the probability distribution of eq.…”

Cosmological constraints from large-scale structure growth rate measurements

“…In the ΛCDM model the growth factor data favor a higher best-fit value of a negative spatial curvature parameter Ω k0 ¼ 1 − Ω m0 − Ω Λ (which corresponds to a closed, spherical spatial geometry) along with a higher best-fit value of Ω m0 compared to what other cosmological tests favor, such as SNIa, Hubble parameter measurements, baryon acoustic oscillations (BAO), and cosmic microwave background (CMB) (see, for example, [11][12][13][14][15][16][17][18][19] and references therein). In the case of the XCDM parametrization the growth factor data favor a steeper time dependence of dark energy density and also a higher value of the ordinary matter energy density parameter (i.e., the equation of state parameter w X has a lower best-fit value and Ω m0 has a higher best-fit value) in comparison with constraints derived from the above-mentioned data sets.…”

“…To do so we assume a Gaussian prior for σ 0 8 determined from cluster observations by [33], for spatially flat ΛCDM, with mean σ [33] notes that this relation is also adequate in the nonflat ΛCDM model and for alternative background cosmologies. 4 Then the posterior probability density function that depends only on the cosmological parameters p is given by 1 See, e.g., [11][12][13][14][15][16][17], and [18]; also see [19]. For constraints on these and related models from near-future data see [20][21][22], and references therein.…”

Hubble Parameter Measurement Constraints on the Redshift of the Deceleration–acceleration Transition, Dynamical Dark Energy, and Space Curvature

“…Since median statistics does not make use of individual measurement errors, the resultant central estimate error is larger than that for weighted mean statistics. For discussions and applications of median statistics, see Gott et al (2001), , Hodge et al (2009), Crandall & Ratra (2014, , Ding et al (2015), , and Zheng et al (2016). As in for the earlier H(z) data tabulated in , all median statistics analysis results look reasonable, and since the weighted mean results are also all reasonable and more constraining, going forward we use only weighted mean results.…”