Methods for the detection of gravitational waves from sub-solar mass ultracompact binaries

TL;DR

This paper develops detection methods for sub-solar mass gravitational wave signals, aiming to identify primordial black holes and constrain their role as dark matter using advanced LIGO data.

Contribution

It introduces computationally feasible search techniques for sub-solar mass binaries, enhancing sensitivity to potential primordial black hole signals.

Findings

Proposed methods improve detection sensitivity for low-mass binaries.

Demonstrated how to set upper limits on primordial black hole dark matter fraction.

Showed that advanced LIGO can significantly constrain PBH populations.

Abstract

We describe detection methods for extensions of gravitational wave searches to sub-solar mass compact binaries. Sub-solar mass searches were previously carried out using Initial LIGO, and Advanced LIGO boasts a detection volume approximately 1000 times bigger than Initial LIGO at design sensitivity. Low masses present computational difficulties, and we suggest a way to rein in the increase while retaining a sensitivity much greater than previous searches. Sub-solar mass compact objects are of particular interest because they are not expected to form astrophysically. If detected they could be evidence of primordial black holes (PBH). We consider a particular model of PBH binary formation that would allow LIGO/Virgo to place constraints on this population within the context of dark matter, and we demonstrate how to obtain conservative bounds for the upper limit on the dark matter fraction.