The Hubble constant and dark energy from cosmological distance measures

TL;DR

This paper examines how assumptions about dark energy influence the measurement of the Hubble constant using cosmological data, finding that the constraints are relatively robust against different dark energy models and curvature assumptions.

Contribution

It provides an analysis of the impact of dark energy models and curvature assumptions on the Hubble constant constraints using multiple cosmological observations.

Findings

Hubble constant constraints are not significantly affected by dark energy assumptions.

Constraints remain stable even when assuming a non-flat universe.

Prior choices on Hubble constant influence dark energy and curvature constraints.

Abstract

We study how the determination of the Hubble constant from cosmological distance measures is affected by models of dark energy and vice versa. For this purpose, constraints on the Hubble constant and dark energy are investigated using the cosmological observations of cosmic microwave background, baryon acoustic oscillations and type Ia suprenovae. When one investigates dark energy, the Hubble constant is often a nuisance parameter, thus it is usually marginalized over. On the other hand, when one focuses on the Hubble constant, simple dark energy models such as a cosmological constant and a constant equation of state are usually assumed. Since we do not know the nature of dark energy yet, it is interesting to investigate the Hubble constant assuming some types of dark energy and see to what extent the constraint on the Hubble constant is affected by the assumption concerning dark energy. We show that the constraint on the Hubble constant is not affected much by the assumption for dark energy. We furthermore show that this holds true even if we remove the assumption that the universe is flat. We also discuss how the prior on the Hubble constant affects the constraints on dark energy and/or the curvature of the universe.