Laser Interferometers as Dark Matter Detectors

TL;DR

This paper explores the potential of gravitational-wave detectors to identify dark matter objects through gravitational interactions and possible new forces, proposing that current and future observatories could detect such events or forces.

Contribution

It introduces a novel method for dark matter detection using gravitational-wave observatories and analyzes sensitivity to both gravitational and hypothetical Yukawa forces.

Findings

Detection rate of one dark matter event per ten years with space-based detectors like LISA.

Sensitivity to Yukawa forces exceeds other probes across various parameters.

Event rates could surpass 10 per year with strong Yukawa coupling in ground and space detectors.

Abstract

While global cosmological and local galactic abundance of dark matter is well established, its identity, physical size and composition remain a mystery. In this paper, we analyze an important question of dark matter detectability through its gravitational interaction, using current and next generation gravitational-wave observatories to look for macroscopic (kilogram-scale or larger) objects. Keeping the size of the dark matter objects to be smaller than the physical dimensions of the detectors, and keeping their mass as free parameters, we derive the expected event rates. For favorable choice of mass, we find that dark matter interactions could be detected in space-based detectors such as LISA at a rate of one per ten years. We then assume the existence of an additional Yukawa force between dark matter and regular matter. By choosing the range of the force to be comparable to the size of the detectors, we derive the levels of sensitivity to such a new force, which exceeds the sensitivity of other probes in a wide range of parameters. For sufficiently large Yukawa coupling strength, the rate of dark matter events can then exceed 10 per year for both ground- and space-based detectors. Thus, gravitational-wave observatories can make an important contribution to a global effort of searching for non-gravitational interactions of dark matter.