Enhanced dark matter abundance in first-order phase transitions

Abstract

We propose a novel scenario to obtain the correct relic abundance for thermally underproduced dark matter. This scenario utilizes a strongly first-order phase transition at temperature TPT 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 102TPT≲m≲104TPT. 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 multimessenger 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. Published by the American Physical Society 2024