Effect of inhomogeneities on the expansion rate of the universe
Effect of inhomogeneities on the expansion rate of the universe
While the expansion rate of a homogeneous isotropic universe is simply proportional to the square-root of the energy density, the expansion rate of an inhomogeneous universe also depends on the nature of the density inhomogeneities. In this paper we calculate to second order in perturbation variables the expansion rate of …