Cosmological evolution of thermal relic particles in $f(R)$ gravity

Abstract

By considering $f(R)$ gravity models, the cosmic evolution is modified with respect to the standard $Λ$CDM scenario. In particular, the thermal history of particles results modified. In this paper, we derive the evolution of relics particles (WIMPs) assuming a reliable $f(R)$ cosmological solution and taking into account observational constraints. The connection to the PAMELA experiment is also discussed. Results are consistent with constraints coming from BICEP2 and PLANCK experiments.

8 pages, 4 figures