Ringing Black Hole is Superradiant: Ultra-light Scalar Field

TL;DR

This paper demonstrates that a Schwarzschild black hole can exhibit superradiance with a minimally coupled scalar field during its ring down phase, suggesting new observational possibilities for black hole mergers.

Contribution

It is the first to show superradiance occurs in Schwarzschild black holes with scalar fields during ring down, expanding understanding of black hole interactions.

Findings

Superradiance observed in Schwarzschild black holes with scalar fields.

Absorption cross-section becomes superradiant during ring down.

Potential for new observational signatures of black hole mergers.

Abstract

Superradiance has been studied quite extensively in the context of static (charged) and rotating black hole spacetime. In this paper, we report for the first time that for a minimally coupled scalar field, the absorption cross-section of a Schwarzschild black hole in its ring down phase can be superradiant. Our present result opens up an intriguing possibility of observing the black hole merging phenomena through other fundamental fields.