Thermal behavior of a radially deformed black hole spacetime

TL;DR

This paper investigates how radial deformation in a black hole spacetime affects Hawking radiation and greybody factors, revealing that deformation increases temperature and modifies radiation bounds, offering insights into non-Einsteinian gravity effects.

Contribution

It introduces a model of radially deformed black hole spacetime and analyzes its impact on Hawking radiation and greybody factors, highlighting differences from classical Kerr black holes.

Findings

Radial deformation increases Hawking temperature.

Deformation enhances bounds on greybody factors.

The model allows separation of scalar field equations for analysis.

Abstract

In the present article, we study the Hawking effect and the bounds on greybody factor in a spacetime with radial deformation. This deformation is expected to carry the imprint of a non-Einsteinian theory of gravity, but shares some of the important characteristics of general relativity (GR). In particular, this radial deformation will restore the asymptotic behavior, and also allows for the separation of the scalar field equation in terms of the angular and radial coordinates -- making it suitable to study the Hawking effect and greybody factors. However, the radial deformation would introduce a change in the locations of the horizon, and therefore, the temperature of the Hawking effect naturally alters. In fact, we observe that the deformation parameter has an enhancing effect on both temperature and bounds on the greybody factor, which introduces a useful distinction with the Kerr spacetime. We discuss these effects elaborately, and broadly study the thermal behavior of a radially deformed spacetime.