Nonthermal “WIMP miracle”

Light scalar fields with only gravitational strength couplings are typically present in UV complete theories of physics beyond the standard model. In the early universe it is natural for these fields to dominate the energy density, and their subsequent decay---if prior to big bang nucleosynthesis---will typically yield some dark matter particles in their decay products. In this paper we make the observation that a Nonthermal ``WIMP Miracle'' may result: that is, in the simplest solution to the cosmological moduli problem, nonthermally produced WIMPs can naturally account for the observed dark matter relic density.