FIMP dark matter mediated by massive gauge boson around the phase transition period and the gravitational waves production

TL;DR

This paper investigates a feebly interacting massive particle (FIMP) dark matter model mediated by a massive gauge boson during a phase transition, analyzing its relic density and associated gravitational wave signals from cosmic strings and phase transitions.

Contribution

It provides a detailed calculation of dark matter relic density considering thermal corrections and phase evolution, and evaluates gravitational wave signals from phase transitions and cosmic strings.

Findings

Relic density of FIMP dark matter can be accurately computed with thermal corrections.

Gravitational waves from phase transitions and cosmic strings are predicted within this model.

The model links dark matter production with observable gravitational wave signals.

Abstract

We study the feebly interacting massive particle dark matter whose production processes are significantly affected by the phase evolution and the complicated thermal corrections to the vector boson. We calculate the freeze-in processes to obtain the correct dark matter relic density by enumerating all the possible $1 \leftrightarrow 2$ and $2 \leftrightarrow 2$ processes. The predicted gravitational waves emitted by the first-order phase transitions and the cosmic strings are evaluated.