Mixing of gravitons with photons in primordial magnetic fields

TL;DR

This paper explores how relic gravitons can convert into photons in large-scale primordial magnetic fields, potentially contributing significantly to the cosmic background light and X-ray excess.

Contribution

It demonstrates a high conversion probability of gravitons to photons in post-recombination magnetic fields, suggesting a new mechanism for cosmic background radiation.

Findings

High conversion probability of gravitons to photons after recombination

Produced photons could explain the cosmic X-ray background excess

Potential contribution to the extragalactic background light

Abstract

Here I discuss the conversion of relic gravitons into photons in large scale cosmological magnetic fields. It is shown that the conversion probability is quite large at the post recombination epoch with a rather large density of formed photons. The produced electromagnetic radiation could make a substantial contribution to the cosmic extragalactic background light and even explain the cosmic x ray background excess.