Measuring the Hubble constant and spatial curvature from supernova apparent magnitude, baryon acoustic oscillation, and Hubble parameter data

TL;DR

This paper combines supernova, baryon acoustic oscillation, and Hubble parameter data to refine measurements of the Hubble constant and spatial curvature, showing consistency with CMB-based constraints.

Contribution

It demonstrates that non-CMB data alone provide constraints compatible with CMB data, offering an independent cross-check on cosmological parameters.

Findings

Non-CMB data constraints align with CMB results.

Non-CMB data suggest possible closed spatial geometries.

Constraints from non-CMB data are weaker but consistent with joint analyses.

Abstract

Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only the spatially homogeneous part of the cosmological model, such as Type Ia supernova apparent magnitude, baryon acoustic oscillation distance, and Hubble parameter measurements, can be used in conjunction with the CMB data to more tightly constrain parameters. Recent joint analyses of CMB and such non-CMB data indicate that slightly closed spatial hypersurfaces are favored in nonflat untilted inflation models and that dark energy dynamics cannot be ruled out, and favor a smaller Hubble constant. We show that the constraints that follow from these non-CMB data alone are consistent with those that follow from the CMB data alone and so also consistent with, but weaker than, those that follow from the joint analyses of the CMB and non-CMB data.