Can Old Galaxies at High Redshifts and Baryon Acoustic Oscillations Constrain H0?

Abstract

A new age-redshift test is proposed in order to constrain H0 with basis on the existence of old high redshift galaxies (OHRG). As should be expected, the estimates of H0 based on the OHRG are heavily dependent on the cosmological description. In the flat concordance model (), for example, the value of H0 depends on the mass density parameter M=1 - . Such a degeneracy can be broken trough a joint analysis involving the OHRG and baryon acoustic oscillation (BAO) signature. In the framework of the CDM model our joint analysis yields a value of H0=71+4-4 Mpc-1 (1σ) with the best fit density parameter M=0.270.03. Such results are in good agreement with independent studies from the 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.