Macroscopic Dark Matter Detection with Gravitational Wave Experiments

TL;DR

This paper explores how gravitational wave detectors could identify macroscopic dark matter objects by analyzing their gravitational and force-mediated effects, including the Shapiro delay, with potential to set new constraints on dark matter properties.

Contribution

It derives gauge-invariant observables for transiting dark matter signals in GW detectors, incorporating the Shapiro effect and finite photon travel time, and assesses detection prospects and constraints on fifth forces.

Findings

Shapiro effect can dominate in short-baseline interferometers.

GW detectors can constrain fifth-force interactions between dark matter and baryons.

Proposed experiments could detect or limit dark matter with masses between 10^5 and 10^{15} kg.

Abstract

We study signatures of macroscopic dark matter (DM) in current and future gravitational wave (GW) experiments. Transiting DM with a mass of $\sim10^5-10^{15}$ kg that saturates the local DM density can be potentially detectable by GW detectors, depending on the baseline of the detector and the strength of the force mediating the interaction. In the context of laser interferometers, we derive the gauge invariant observable due to a transiting DM, including the Shapiro effect (gravitational time delay accumulated during the photon propagation), and adequately account for the finite photon travel time within an interferometer arm. In particular, we find that the Shapiro effect can be dominant for short-baseline interferometers such as Holometer and GQuEST. We also find that proposed experiments such as Cosmic Explorer and Einstein Telescope can constrain a fifth force between DM and baryons, at the level of strength $\sim 10^3$ times stronger than gravity for, e.g., kg mass DM with a fifth-force range of $10^6$ m.