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 104 binary black holes coalescence events would constrain the abundance of compact DM to ∼10−3. It suggests that searching for and identifying micro-lensing signatures in future detections could be complementary and helpful in constraining compact DM scenarios.
@article{arxiv.2508.13577,
title = {Constraints on Compact Dark Matter Population from Micro-lensing Effect of Gravitational Wave for the third-generation gravitational Wave Detector},
author = {Xin-Yi Lin and Xi-Jing Wang and Huan Zhou and Zhengxiang Li and Kai Liao and Zong-Hong Zhu},
journal= {arXiv preprint arXiv:2508.13577},
year = {2025}
}