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

Understand

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.