Gravitational waves from superradiant instabilities of rotating black holes

TL;DR

This paper reviews how ultralight bosons could cause superradiant instabilities in rotating black holes, leading to gravitational wave signals that could help identify dark matter candidates with current and future detectors.

Contribution

It provides an overview of superradiant instabilities caused by ultralight bosons and evaluates detection prospects with gravitational wave observatories.

Findings

Superradiant instabilities can produce detectable gravitational waves.

Current detectors have limited sensitivity to these signals.

Future detectors could significantly improve detection prospects.

Abstract

Direct detection of gravitational waves from several compact binary coalescences has ushered in a new era of astronomy. It has opened up the possibility of detecting ultralight bosons, predicted by extensions of the Standard Model, from their gravitational signatures. This is of particular interest as some of these hypothetical particles could be components of dark matter that are expected to interact very weakly with Standard Model particles, if at all, but they would gravitate as usual. Ultralight bosons can trigger superradiant instabilities of rotating black holes and form bosonic clouds that would emit gravitational waves. In this article we present an overview of such instabilities as gravitational wave sources and assess the ability of current and future detectors to shed light on potential dark matter candidates.