Absorption and scattering of a black hole with a global monopole in f(R) gravity

TL;DR

This paper investigates how a global monopole and modifications in gravity affect the scattering and absorption of black holes, revealing that these factors alter the cross sections especially at low frequencies and small angles.

Contribution

It introduces a model combining a global monopole with f(R) gravity to analyze black hole scattering and absorption, highlighting the effects of these modifications on cross sections.

Findings

Absorption cross section proportional to the event horizon area at low frequencies.

Global monopole and f(R) gravity modify scattering and absorption cross sections.

Low-frequency and small-angle limits show significant deviations due to the monopole and gravity modifications.

Abstract

In this paper we consider the solution of a black hole with a global monopole in $f(R)$ gravity and apply the partial wave approach to compute the differential scattering cross section and absorption cross section. We show that in the low-frequency limit and at small angles the contribution to the dominant term in the scattering/absorption cross section is modified by the presence of the global monopole and the gravity modification. In such limit, the absorption cross section shows to be proportional to the area of the event horizon.