Mimetic Dark Matter from Inflation

TL;DR

This paper explores how coupling mimetic dark matter to the Gauss-Bonnet term during inflation can naturally produce the correct amount of dark matter, with potential modifications to its post-inflation behavior.

Contribution

It introduces a novel coupling mechanism between mimetic dark matter and the Gauss-Bonnet term that generates dark matter during inflation.

Findings

Correct dark matter abundance is produced at the end of inflation.

The coupling influences the post matter-radiation equality behavior.

The energy density relates to the Hubble parameter at inflation's end.

Abstract

We investigate the coupling of mimetic dark matter to the Gauss-Bonnet topological term in addition to the Einstein-Hilbert action. We demonstrate that such interactions can naturally give rise to mimetic dark matter during the inflationary stage of the universe's evolution. By choosing an appropriate coupling between the mimetic field and the Gauss-Bonnet term, we find that at the end of inflation, the correct amount of dust-like dark matter is produced, with its energy density expressible in terms of the Hubble parameter at the end of inflation. Furthermore, depending on the form of the coupling, the post matter-radiation equality behavior of mimetic dark matter can experience slight modifications.