Analog Schwarzschild black holes of Bose-Einstein condensates in a cavity: Quasinormal modes and quasibound states

TL;DR

This paper analyzes the spectral properties of analog Schwarzschild black holes created with Bose-Einstein condensates in a cavity, revealing similarities with gravitational black holes and potential for experimental testing of quantum phenomena.

Contribution

It provides a detailed spectral analysis of a tabletop acoustic black hole and its higher-dimensional analog, highlighting quasinormal modes and quasibound states with implications for experiments.

Findings

Quasinormal modes resemble those of gravitational black holes.

Existence of a phonon sphere analogous to the photon sphere.

Potential for experimental verification of Hawking radiation in condensate systems.

Abstract

Analog models of black holes have unequivocally proven to be extremely beneficial in providing critical information regarding black hole spectroscopy, superradiance, quantum phenomena and most importantly Hawking radiation and black hole evaporation; topics that have either recently begun to bloom through gravitational wave observations or have not yet been investigated in astrophysical setups. Black hole analog experiments have made astonishing steps toward the aforementioned directions and are paramount in understanding the quantum nature of the gravitational field. Recently, a tabletop analog Schwarzschild black hole has been proposed by placing Bose-Einstein condensates of photons inside a mirror's cavity, leading to a sink with a radial vortex that represents a velocity singularity. Here, we provide an extensive spectral analysis of both the tabletop acoustic black hole and its higher-dimensional gravitational analog. We find that quasinormal modes and quasibound states share qualitative similarities in both systems and show that the eikonal quasinormal modes of the analog acoustic black hole have a photon-sphere-like interpretation, which points to the existence of a phonon sphere in the analog black hole. Our results, complemented with the recently calculated graybody factors and Hawking radiation of the acoustic analog, can provide a theoretical test bed for future tabletop experiments with condensates of light in a mirror's cavity and provide significant insights regarding classical and quantum phenomena in higher-dimensional black holes.