Cosmological constraints from higher-redshift gamma-ray burst, HII starburst galaxy, and quasar (and other) data

TL;DR

This study combines gamma-ray burst, HII galaxy, and quasar data to constrain cosmological models, finding results consistent with a flat universe and a cosmological constant, while allowing for mild deviations.

Contribution

It provides the first joint analysis of these high-redshift data sets to constrain cosmological parameters, demonstrating their mutual consistency and compatibility with standard cosmological models.

Findings

Consistent constraints on matter density and Hubble constant from combined data.

Results support a flat universe with a cosmological constant.

Including quasar flux data does not significantly alter conclusions.

Abstract

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are mutually consistent. Cosmological constraints from a joint analysis of these data sets are largely consistent with currently-accelerating cosmological expansion as well as with cosmological constraints derived from a combined analysis of Hubble parameter ($H(z)$) and baryon acoustic oscillation (BAO, with Planck-determined baryonic matter density) measurements. A joint analysis of the $H(z)$ + BAO + QSO-AS + HIIG + GRB data provides fairly model-independent determinations of the non-relativistic matter density parameter $\Omega_{\rm m_0}=0.313\pm0.013$ and the Hubble constant $H_0=69.3\pm1.2\ \rm{km \ s^{-1} \ Mpc^{-1}}$. These data are consistent with the dark energy being a cosmological constant and with spatial hypersurfaces being flat, but they do not rule out mild dark energy dynamics or a little spatial curvature. We also investigate the effect of including quasar flux measurements in the mix and find no novel conclusions.