Hidden Dark Matter from Starobinsky Inflation

TL;DR

This paper explores how minimal extensions of Starobinsky inflation can produce dark matter particles, including dark glueballs, through inflaton decay, and discusses their viability and testability within observational constraints.

Contribution

It introduces scenarios where dark glueballs and other dark-sector particles from inflaton decay serve as dark matter candidates, addressing production and observational viability.

Findings

Dark glueballs can be produced via inflaton decay but face constraints on coldness and self-interaction.

Proposed scenarios make dark glueballs and other particles viable dark matter candidates.

Discussion of potential observational tests for these dark matter scenarios.

Abstract

The Starobinsky inflation model is one of the simplest inflation models that is consistent with the cosmic microwave background observations. In order to explain dark matter of the universe, we consider a minimal extension of the Starobinsky inflation model with introducing the dark sector which communicates with the visible sector only via the gravitational interaction. In Starobinsky inflation model, a sizable amount of dark-sector particle may be produced by the inflaton decay. Thus, a scalar, a fermion or a vector boson in the dark sector may become dark matter. We pay particular attention to the case with dark non-Abelian gauge interaction to make a dark glueball a dark matter candidate. In the minimal setup, we show that it is difficult to explain the observed dark matter abundance without conflicting observational constraints on the coldness and the self-interaction of dark matter. We propose scenarios in which the dark glueball, as well as other dark-sector particles, from the inflaton decay become viable dark matter candidates. We also discuss possibilities to test such scenarios.