Charged superradiant instability in a spherical regular black hole

TL;DR

This paper investigates the charged superradiant instability in a specific regular black hole model, revealing conditions under which the instability occurs and its potential astrophysical implications.

Contribution

It introduces a new analysis of superradiant instability in a deformed Minkowski-based regular black hole, highlighting parameter effects and instability growth rates.

Findings

Instability occurs only within a specific deformation parameter range.

Maximum growth rate of instability is approximately 10^{-3}.

Instability is more significant than in previously studied ABG black holes.

Abstract

We examine the stability of a spherically symmetric regular black hole when subjected to perturbations from a charged scalar field. This particular black hole is constructed by deforming the Minkowski spacetime. It has been observed that the charged superradiant instability arises only within a specific range of the deformation parameter, potentially resulting in an instability growth rate with a maximum magnitude of approximately $\text{Im} (M \omega) \sim 10^{-3}$. This growth rate significantly exceeds the instability identified in ABG black holes discussed in prior research, suggesting a notable timescale for detecting this phenomenon in astrophysical scenarios. Additionally, we conduct a thorough investigation into how the three parameters of the model influence the onset and intensity of the instability. Our analysis offers further insights into the possible emergence of this instability in spherically regular black holes and its association with the nonlinear effects of the electromagnetic field.