The Hubble constant and dark energy

TL;DR

This paper investigates the robustness of the Hubble constant measurement from CMB anisotropy against various dark energy models, including phantom power, textures, and curvature, and derives related observational constraints.

Contribution

It demonstrates the independence of the Hubble constant from small modifications to dark energy models and provides new constraints on these models using supernova, 2df, and SDSS data.

Findings

Hubble constant remains stable under certain dark energy modifications

Constraints on phantom power, textures, and curvature from supernova observations

Adjusted matter density estimates from cosmic perturbations and CMB

Abstract

The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy. Modifications of the Friedmann equation to include phantom power (w < -1), textures (w = -2/3) and curvature are considered, and constraints on these dark energy contributors from supernova observations are derived. Modified values for the density of matter inferred from cosmic density perturbations and from the CMB under these circumstances are also estimated, as exemplified by 2df and SDSS.