Gravitational dark matter production: Primordial black holes and UV freeze-in

Dark matter (DM) interacting only gravitationally with the standard model could have been produced in the early universe by Hawking evaporation of primordial black holes (PBH). This mechanism is viable in a large range of DM mass, spanning up to the Planck scale. However, DM is also unavoidably produced by the irreducible UV gravitational freeze-in. We show that the latter mechanism sets strong bounds, excluding large regions of the parameter space favored by PBH production. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

Research suggests that dark matter in the early universe may have been produced by the Hawking evaporation of primordial black holes. However, dark matter is also inevitably produced by UV gravitational freeze-in, which imposes strong constraints on the parameter space favored by primordial black hole production.