Enhanced Dark Matter Abundance in First-Order Phase Transitions

TL;DR

This paper introduces a new mechanism where a first-order phase transition enhances dark matter relic abundance, predicts detectable gravitational waves, and offers a multi-messenger approach to probe underlying particle physics models.

Contribution

It presents a novel scenario linking first-order phase transitions to dark matter abundance and gravitational wave signals, expanding the methods to test dark matter models.

Findings

Dark matter relic abundance can be achieved via a first-order phase transition.

Gravitational waves from the phase transition are within reach of upcoming detectors.

The scenario allows for multi-messenger probes combining gravitational waves and dark matter searches.

Abstract

We propose a novel scenario to obtain the correct relic abundance for thermally under-produced dark matter. This scenario utilizes a strongly first-order phase transition at temperature $T_{\rm PT}$ that gives rise to dark matter mass $m$. Freeze-out in the broken phase can yield the desired abundance in the entire region currently allowed by observational bounds and theoretical constraints for $10^2 T_{\rm PT} \lesssim m \lesssim 10^4 T_{\rm PT}$. We show that the accompanying gravitational waves are strong enough to be detected by many upcoming and proposed experiments. This, in tandem with dark matter indirect searches, provides a multi-messenger probe of such models. Positive signals in the future can help reconstruct the potential governing the phase transition and shed light on an underlying particle physics realization.