Quasinormal modes, Superradiance and Area Spectrum for 2+1 Acoustic Black Holes

TL;DR

This paper derives exact quasinormal modes for a rotating 2+1 acoustic black hole, analyzes superradiance, and proposes an area spectrum based on quantization rules, advancing understanding of acoustic black hole physics.

Contribution

It provides the first exact quasinormal mode expression for 2+1 acoustic black holes and links superradiance with area quantization.

Findings

Exact quasinormal modes derived for rotating 2+1 acoustic black holes

Superradiance phenomena analyzed for pure spinning acoustic black holes

Proposed area spectrum based on Bohr-Sommerfeld quantization

Abstract

We present an exact expression for the quasinormal modes of acoustic disturbances in a rotating 2+1 dimensional sonic black hole (draining bathtub fluid flow) in the low frequency limit and evaluate the adiabatic invariant proposed by Kunstatter. We also compute,via Bohr-Sommerfeld quantization rule the equivalent area spectrum for this acoustic black hole, and we compute the superradiance phenomena for pure spinning 2+1 black holes.