Probing Gravitational Dark Matter with Ultra-high Frequency Gravitational Waves

TL;DR

This paper explores how ultra-high frequency gravitational wave detectors could reveal properties of gravitational dark matter, which interacts only through gravity and is difficult to detect directly.

Contribution

It establishes a link between thermal gravitational waves and gravitational dark matter properties, proposing a new method to probe dark matter characteristics.

Findings

Future ultra-high frequency GW experiments can determine dark matter mass and spin.

A connection between thermal GWs and gravitational DM properties is established.

Potential to detect gravitational DM through GW amplitude measurements.

Abstract

The evidence for the existence of dark matter (DM) is compelling, yet its nature remains elusive. A minimal scenario involves DM interacting solely through gravity. However, the detection would be extremely challenging. In the early Universe, such DM can be unavoidably generated via annihilation of particles in the standard model (SM) thermal plasma. It is known that the SM thermal plasma also produces gravitational waves (GWs). In this study, we establish a simple connection between the amplitude of thermal GWs and the properties of pure gravitational DM. Notably, future GW experiments in the ultra-high frequency regime have the potential to shed light on the mass and spin of pure gravitational DM.