Acoustic Black Hole in Hayward Spacetime: Shadow, Quasinormal Modes and Analogue Hawking Radiation

TL;DR

This study models an acoustic black hole in Hayward spacetime, analyzing its shadow, quasinormal modes, and Hawking radiation analogue, revealing how tuning parameters influence stability, emission, and shadow size, with potential astrophysical implications.

Contribution

It introduces an acoustic black hole model in Hayward spacetime and analyzes its properties using the WKB method, highlighting stability and emission characteristics not previously explored.

Findings

QNM frequencies are more stable than those of the Hayward black hole.

Grey-body factor and energy emission rate increase with the tuning parameter.

Acoustic shadow radius enlarges as the tuning parameter increases.

Abstract

In this paper, we study an acoustic black hole in Hayward spacetime from the relativistic Gross-Pitaevskii theory. By examining the critical null geodesics, the shadow of the acoustic horizon is sketched. Then the quasinormal mode (QNM) frequencies of the acoustic Hayward black hole are computed numerically using the WKB method, which are shown to be more stable than those of the Hayward black hole, and the variations in the QNM frequencies are shown to correlate with the behavior of the effective potential. Moreover, the WKB method is also employed to calculate the grey-body factor and energy emission rate of the analogue Hawking radiation. It is shown that, as the tuning parameter increases, both the grey-body factor and the energy emission rate are enhanced, which can likewise be attributed to changes in the effective potential. Besides, the radius of acoustic shadow increases with the tuning parameter as well. Our results not only construct an acoustic black hole in regular black hole spacetime, but may also provide potential applications in future observations of astrophysical black holes.