SIMBAD references

A new age–redshift test is proposed in order to constrain H₀on the basis of the existence of old high-redshift galaxies (OHRGs). In the flat Λ cold dark matter model, the value of H₀ is heavily dependent on the mass density parameter Ω_M= 1 - Ω_Λ. Such a degeneracy can be broken through a joint analysis involving the OHRG and baryon acoustic oscillation signature. By assuming a galaxy incubation time, t_inc= 0.8±0.4 Gyr, our joint analysis yields a value of H₀= 71 ±4 km/s/Mpc (1σ) with the best-fit density parameter Ω_ M_= 0.27±0.03. Such results are in good agreement with independent studies from the Hubble Space Telescope key project and recent estimates of the Wilkinson Microwave Anisotropy Probe, thereby suggesting that the combination of these two independent phenomena provides an interesting method to constrain the Hubble constant.