Constraints on Compact Dark Matter Population from Micro-lensing Effect of Gravitational Wave for the third-generation gravitational Wave Detector

TL;DR

This paper explores how future gravitational wave observations with the Einstein Telescope can constrain the abundance of compact dark matter, like primordial black holes, through micro-lensing signatures in GW signals.

Contribution

It introduces a method to simulate and analyze micro-lensing effects on GWs using hierarchical Bayesian inference for the third-generation detector data.

Findings

Detection of several micro-lensing GW signals can constrain compact DM abundance to ~10^{-3}.

Simulations show micro-lensing signatures are detectable with future GW data.

Micro-lensing analysis provides a complementary approach to traditional dark matter constraints.

Abstract

Since the pioneering detection of gravitational wave (GW) from a binary black hole merger by the LIGO-Virgo collaboration, GW has become a powerful probe for astrophysics and cosmology. If compact dark matter (DM) candidates, e.g. primordial black holes, contribute a substantial fraction of the DM component across a broad mass range, they would yield distinctive micro-lensing signatures on GW signals. In this paper, based on the third-generation ground-based GW detector, i.e. Einstein Telescope, we propose to constrain population information of compact DM by simulating micro-lensing GWs and analyzing with the hierarchical Bayesian inference framework. For a population with a power-law mass function, we demonstrate that detections of several micro-lensing GW signals in $10^4$ binary black holes coalescence events would constrain the abundance of compact DM to $\sim10^{-3}$. It suggests that searching for and identifying micro-lensing signatures in future detections could be complementary and helpful in constraining compact DM scenarios.