Legacy of boson clouds on black hole binaries

TL;DR

This paper explores how ultralight boson clouds around black holes influence gravitational wave signals, revealing two main outcomes that could help detect new fundamental particles through future observations.

Contribution

It analyzes the evolution of boson clouds in black hole binaries, identifying distinct waveform imprints and conditions under which clouds survive or are destroyed, aiding in new boson detection.

Findings

Two possible resonance outcomes with distinct waveform signatures

Cloud survival depends on binary and cloud rotation alignment

Potential to infer new boson existence from gravitational wave data

Abstract

Superradiant clouds of ultralight bosons can leave an imprint on the gravitational waveform of black hole binaries through "ionization" and "resonances." We study the sequence of resonances as the binary evolves, and show that there are only two possible outcomes, each with a distinct imprint on the waveform. If the cloud and the binary are nearly counter-rotating, then the cloud survives in its original state until it enters the sensitivity band of future gravitational wave detectors, such as LISA. In all other cases, resonances destroy the cloud, while driving the binary to co-rotate with it and its eccentricity close to a fixed point. This opens up the possibility of inferring the existence of a new boson from the statistical analysis of a population of black hole binaries.