Correlated gravitational wave and microlensing signals of macroscopic dark matter

TL;DR

This paper explores how certain dark matter structures called Fermi balls, formed during a phase transition, could produce detectable correlated signals in gravitational waves and microlensing observations.

Contribution

It demonstrates the potential for simultaneous detection of Fermi balls through gravitational wave and microlensing signals, linking dark matter physics with observational astronomy.

Findings

Fermi balls of specific mass range can produce detectable signals.

Correlated gravitational wave and microlensing observations are feasible.

Detection prospects are outlined for upcoming observatories.

Abstract

Fermion dark matter particles can aggregate to form extended dark matter structures via a first-order phase transition in which the particles get trapped in the false vacuum. We study Fermi balls created in a phase transition induced by a generic quartic thermal effective potential. We show that for Fermi balls of mass, $3\times 10^{-12}M_\odot \lesssim M_{\rm FB} \lesssim 10^{-5}M_\odot$, correlated observations of gravitational waves produced during the phase transition (at SKA/THEIA/$\mu$Ares), and gravitational microlensing caused by Fermi balls (at Subaru-HSC), can be made.