Primordial dark matter from curvature induced symmetry breaking

Abstract

We demonstrate that adiabatic dark matter can be generated by gravity induced symmetry breaking during inflation. We study a Z2 symmetric scalar singlet that couples to other fields only through gravity and for which the symmetry is broken by the spacetime curvature during inflation when the non-minimal coupling ξ is negative. We find that the symmetry breaking leads to the formation of adiabatic dark matter with the observed abundance for the singlet mass m~MeV and |ξ|~ 1.