Can Old Galaxies at High Redshifts and Baryon Acoustic Oscillations Constrain H_0?

TL;DR

This paper proposes a new method combining old high redshift galaxy data and baryon acoustic oscillations to constrain the Hubble constant, achieving results consistent with other measurements.

Contribution

It introduces a novel age-redshift test that, when combined with BAO data, effectively constrains H_0 and breaks degeneracies in cosmological models.

Findings

H_0 estimated as 71^{+4}_{-4} km/s/Mpc in the b4CDM model

Best fit b4M = 0.27 b1 0.03

Results agree with HST and WMAP estimates

Abstract

A new age-redshift test is proposed in order to constrain $H_0$ with basis on the existence of old high redshift galaxies (OHRG). As should be expected, the estimates of $H_0$ based on the OHRG are heavily dependent on the cosmological description. In the flat concordance model ($\Lambda$CDM), for example, the value of $H_0$ depends on the mass density parameter $\Omega_M=1 - \Omega_{\Lambda}$. Such a degeneracy can be broken trough a joint analysis involving the OHRG and baryon acoustic oscillation (BAO) signature. In the framework of the $\Lambda CDM$ model our joint analysis yields a value of $H_0=71^{+4}_{-4}\kms$ Mpc$^{-1}$ ($1\sigma$) with the best fit density parameter $\Omega_M=0.27\pm0.03$. Such results are in good agreement with independent studies from the {\it{Hubble Space Telescope}} key project and the recent estimates of WMAP, thereby suggesting that the combination of these two independent phenomena provides an interesting method to constrain the Hubble constant.