Quasar X-ray and UV flux, baryon acoustic oscillation, and Hubble parameter measurement constraints on cosmological model parameters

TL;DR

This study combines quasar X-ray/UV flux data with BAO and H(z) measurements to constrain cosmological models, finding consistency with the standard model but slight preferences for closed geometry and dynamic dark energy.

Contribution

It introduces a comprehensive analysis using a large quasar dataset combined with BAO and H(z) data to refine cosmological parameter constraints.

Findings

QSO data constraints are weaker but consistent with other measurements.

Joint analysis supports the flat ΛCDM model but suggests possible closed geometry.

Results mildly favor dynamical dark energy over a cosmological constant.

Abstract

We use the Risaliti & Lusso (2015) compilation of 808 X-ray and UV flux measurements of quasars (QSOs) in the redshift range $0.061 \leq z \leq 6.28$, alone and in conjuction with baryon acoustic oscillation (BAO) and Hubble parameter [$H(z)$] measurements, to constrain cosmological parameters in six cosmological models. The QSO data constraints are significantly weaker than, but consistent with, those from the $H(z)$ + BAO data. A joint analysis of the QSO + $H(z)$ + BAO data is consistent with the current standard model, spatially-flat $\Lambda$CDM, but mildly favors closed spatial hypersurfaces and dynamical dark energy.