Do the age of the Universe and the Hubble constant depend on what scale one observes them?

Abstract

The apparent cosmological conict between the age of the Universe, predicted in the standard Friedman cosmology by using the recent measurement of the larger Hubble constant from a direct calibration of the distance to the Virgo galaxy cluster, and the ages of the oldest stars and globular clusters is resolved by i n v oking the scale dependence of cosmological quantities, including the age of the Universe. The distance dependence or the running of cosmological quantities is motivated by the asymptotically-free higher-derivative quantum gravity. The running can also be derived by \properly" modifying the Friedman equations. This property can also provide partial explanation of the apparent disagreement b e t w een the two recent measurements of the Hubble constant using NGC 4571 at 15 Mpc and NGC 5253 at 4 Mpc.

Astrophysical and Cosmological Constraints on a Scale-Dependent Gravitational Coupling

“…Furthermore, due to the increase in the gravitational constant on large scales one finds that the energy density fluctuations grow quicker than in usual matter dominated Friedmann-Robertson-Walker models. Moreover, one can naturally explain with a scale-dependent G the discrepancy between determinations of the Hubble's parameter made at different scales, as suggested in [6], and recently studied in [9]. Nevertheless, independently of the possible running of the gravitational constant in a higher derivative theory of gravity, it is certainly worthwhile analysing the constraints on the scaledependence of G from astrophysical and cosmological phenomena, where such an effect would be dominant.…”

“…Furthermore, from Eq. (3) one can clearly see the scale dependence of the Hubble parameter [6,7,9]. In view of the above arguments, the criticism raised in Ref.…”