Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration-Acceleration Transition Redshift, and Spatial Curvature

• Published in: The Astrophysical journal Vol. 856; no. 1; pp. 3 - 13
• Main Authors: Yu, Hai, Ratra, Bharat, Wang, Fa-Yin
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 20.03.2018; IOP Publishing; Institute of Physics (IOP)
• Subjects: Acceleration; Acoustic measurement; ASTRONOMY AND ASTROPHYSICS; Astrophysics; Baryons; Continuity (mathematics); cosmological parameters; cosmology: observations; Curvature; Deceleration; Gaussian process; Hubble constant; large-scale structure of universe; Mathematical models; Parameters; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Red shift
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/aab0a2

We compile a complete collection of reliable Hubble parameter H(z) data to redshift z ≤ 2.36 and use them with the Gaussian Process method to determine continuous H(z) functions for various data subsets. From these continuous H(z)'s, summarizing across the data subsets considered, we find H0 ∼ 67 4 km s−1 Mpc−1, more consistent with the recent lower values determined using a variety of techniques. In most data subsets, we see a cosmological deceleration-acceleration transition at 2 significance, with the data subsets transition redshifts varying over at 1 significance. We find that the flat-ΛCDM model is consistent with the H(z) data to a z of 1.5 to 2.0, depending on data subset considered, with 2 deviations from flat-ΛCDM above this redshift range. Using the continuous H(z) with baryon acoustic oscillation distance-redshift observations, we constrain the current spatial curvature density parameter to be , consistent with a flat universe, but the large error bar does not rule out small values of spatial curvature that are now under debate.