Gravitational production of super-Hubble-mass particles: an analytic approach

Abstract

Through a mechanism similar to perturbative particle scattering, particles of mass m_χ larger than the Hubble expansion rate H_inf during inflation can be gravitationally produced at the end of inflation without the exponential suppression powers of exp(−m_χ/H_inf ). Here we develop an analytic formalism for computing particle production for such massive particles. We apply our formalism to specific models that have been previously been studied only numerically, and we find that our analytical approximations reproduce those numerical estimates well.