Gravitational waves from thermal heavy scalar dark matter

TL;DR

This paper introduces a heavy scalar dark matter model with a dilaton mediator that induces a strong first-order electroweak phase transition, producing detectable gravitational waves for future space-based detectors.

Contribution

It presents a novel scalar extension of the Standard Model that predicts observable gravitational wave signals from early universe phase transitions.

Findings

Strong first-order electroweak phase transition due to supercooling

Predicted gravitational wave signals within detectable frequency range

Model viable for heavy scalar dark matter with Higgs portal

Abstract

We propose a gauge singlet scalar with mass around 1-100 TeV as a thermal heavy dark matter candidate along with a dilaton as a Higgs portal mediator in a dimensionless scalar extension of the Standard Model. We demonstrate analytically that such a model gives rise to very strong first-order electroweak phase transition through supercooling. We calculate the corresponding gravitational wave signals due to bubble collisions during the phase transition. The produced gravitational waves can be detected by future space-based gravitational wave detectors in the frequency range from 10^{-4} Hz to 0.1 Hz.