Stationary Scalar Clouds Around Rotating Black Holes

TL;DR

This paper demonstrates the existence of stationary scalar field configurations, or 'clouds', around rapidly rotating black holes, suggesting potential dark matter structures in such extreme environments.

Contribution

It analytically shows the existence and properties of stationary scalar clouds around maximally rotating Kerr black holes, advancing understanding of wave dynamics in strong gravity.

Findings

Stationary scalar clouds exist around maximally rotating black holes.

The effective height of scalar clouds is analytically determined.

Results support the possibility of scalar dark matter distributions near black holes.

Abstract

Motivated by novel results in the theory of wave dynamics in black-hole spacetimes, we analyze the dynamics of a massive scalar field surrounding a rapidly rotating Kerr black hole. In particular, we report on the existence of stationary (infinitely long-lived) regular field configurations in the background of maximally rotating black holes. The effective height of these scalar "clouds" above the central black hole is determined analytically. Our results support the possible existence of stationary scalar field dark matter distributions surrounding rapidly rotating black holes.