Discovering intermediate-mass black hole lenses through gravitational wave lensing

TL;DR

This paper explores the potential to detect intermediate-mass black holes by observing their gravitational lensing effects on gravitational waves in the LIGO-Virgo detector network, demonstrating high-confidence detection possibilities.

Contribution

It introduces a simulation-based method to identify intermediate-mass black hole lenses through gravitational wave lensing, highlighting the detectability in current gravitational wave observatories.

Findings

Intermediate-mass black holes can be detected with 98% confidence via gravitational wave lensing.

Simulations show detectable lensing effects across a wide range of binary and lens parameters.

Gravitational wave lensing offers a promising avenue to discover missing intermediate-mass black holes.

Abstract

Intermediate-mass black holes are the missing link that connects stellar-mass to supermassive black holes and are key to understanding galaxy evolution. Gravitational waves, like photons, can be lensed, leading to discernable effects such as diffraction or repeated signals. We investigate the detectability of intermediate-mass black hole deflectors in the LIGO-Virgo detector network. In particular, we simulate gravitational waves with variable source distributions lensed by an astrophysical population of intermediate-mass black holes, and use standard LIGO tools to infer the properties of these lenses. We find detections of intermediate-mass black holes at $98\%$ confidence level over a wide range of binary and lens parameters. Therefore, we conclude that intermediate-mass black holes could be detected through lensing of gravitational waves in the LIGO-Virgo detector network.