Relic Density of Asymmetric Dark Matter in Modified Cosmological Scenarios

Abstract

We discuss the relic abundance of asymmetric Dark Matter particles in modified cosmological scenarios where the Hubble rate is changed with respect to the standard cosmological scenario. The modified Hubble rate leaves its imprint on the relic abundance of asymmetric Dark Matter particles if the asymmetric Dark Matter particles freeze--out in this era. For generality we parameterize the modification of the Hubble rate and then calculate the relic abundance of asymmetric Dark Matter particles and anti--particles. We found the abundances for the Dark Matter particles and anti--particles are enhanced in the modified cosmological models. The indirect detection signal is possible for the asymmetric Dark Matter particles due to the increased annihilation rate in the modified cosmological models. Applying Planck data, we find the constraints on the parameters of the modified cosmological models.