Gravitational waves from dark sectors, oscillating inflatons, and mass boosted dark matter

Gravitational wave signatures from dynamical scalar field configurations provide a compelling observational window on the early universe. Here we identify intriguing connections between dark matter and scalars fields that emit gravitational waves, either through a first order phase transition or oscillating after inflation. To study gravitational waves from first order phase transitions, we investigate a simplified model consisting of a heavy scalar coupled to a vector and fermion field. We then compute gravitational wave spectra sourced by inflaton field configurations oscillating after E-Model and T-Model inflation. Some of these gravitational wave signatures can be uncovered by the future Big Bang Observatory, although in general we find that MHz-GHz frequency gravitational wave sensitivity will be critical for discovering the heaviest dark sectors. Intriguingly, we find that scalars undergoing phase transitions, along with E-Model and T-Model potentials, can impel a late-time dark matter mass boost and generate up to Planck mass dark matter. For phase transitions and oscillating inflatons, the largest dark matter mass boosts correspond to higher amplitude stochastic gravitational wave backgrounds.

Automated summary

Studying gravitational wave signatures from first order phase transitions and oscillations after inflation reveals interesting connections between dark matter and scalar fields, with MHz-GHz gravitational wave sensitivity being crucial for discovering the heaviest dark sectors. The study also finds that scalar fields undergoing phase transitions and E-Model or T-Model potentials can lead to late-time dark matter mass boosts, potentially generating dark matter masses up to the Planck mass. Additionally, higher amplitude stochastic gravitational wave backgrounds correspond to the largest dark matter mass boosts in phase transitions and oscillating inflatons.