Dark photon dark matter from charged inflaton

TL;DR

This paper proposes a new mechanism for producing vector dark matter during inflation via a charged inflaton field, resulting in dark photons that can account for the observed relic density.

Contribution

It introduces a model where a charged inflaton generates massive dark photons during inflation, explaining dark matter relic abundance with a novel production process.

Findings

Dark photons can acquire mass larger than the Hubble scale during inflation.

Quantum fluctuations of dark photons can produce the observed dark matter density.

Either transverse or longitudinal modes can dominate the dark matter production.

Abstract

We present a scenario of vector dark matter production during inflation containing a complex inflaton field which is charged under a dark gauge field and which has a symmetry breaking potential. As the inflaton field rolls towards the global minimum of the potential the dark photons become massive with a mass which can be larger than the Hubble scale during inflation. The accumulated energy of the quantum fluctuations of the produced dark photons gives the observed relic density of the dark matter for a wide range of parameters. Depending on the parameters, either the transverse modes or the longitudinal mode or their combination can generate the observed dark matter relic energy density.