Using lower-redshift, non-CMB, data to constrain the Hubble constant and other cosmological parameters

TL;DR

This study uses diverse lower-redshift observational data to constrain cosmological parameters, providing model-independent estimates of the Hubble constant and matter density, and comparing model fits with Planck CMB results.

Contribution

It offers the first comprehensive joint analysis of multiple non-CMB lower-redshift data sets to constrain cosmological parameters independently of the CMB.

Findings

Estimated Hubble constant: 69.7±1.2 km/s/Mpc

Matter density parameter: 0.295±0.017

Flat ΛCDM model is most favored but alternative models are not ruled out

Abstract

We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst data, to jointly constrain cosmological parameters in six cosmological models. The joint analysis provides model-independent determinations of the Hubble constant, $H_0=69.7\pm1.2$ $\rm{km \ s^{-1} \ Mpc^{-1}}$, and the current non-relativistic matter density parameter, $\Omega_{m0}=0.295\pm0.017$. These error bars are factors of 2.2 and 2.3 larger than the corresponding error bars in the flat $\Lambda$CDM model from Planck TT,TE,EE+lowE+lensing cosmic microwave background anisotropy data. Based on the deviance information criterion (DIC), the flat $\Lambda$CDM model is most favored but mild dark energy dynamics and a little spatial curvature are not ruled out.