Semiclassical approach to black hole absorption of electromagnetic radiation emitted by a rotating charge

TL;DR

This paper uses a semiclassical quantum field theory approach to analyze electromagnetic radiation emitted by a rotating charge near a Schwarzschild black hole, focusing on absorption and emission characteristics.

Contribution

It introduces a semiclassical method employing Gupta-Bleuler quantization to study electromagnetic radiation from a rotating charge around a black hole, highlighting polarization effects.

Findings

Most photons escape to infinity, with some absorbed by the black hole.

Photon polarizations contribute differently to emitted power.

Results compared with Newtonian orbit assumptions.

Abstract

We consider an electric charge, minimally coupled to the Maxwell field, rotating around a Schwarzschild black hole. We investigate how much of the radiation emitted from the swirling charge is absorbed by the black hole and show that most of the photons escape to infinity. For this purpose we use the Gupta-Bleuler quantization of the electromagnetic field in the modified Feynman gauge developed in the context of quantum field theory in Schwarzschild spacetime. We obtain that the two photon polarizations contribute quite differently to the emitted power. In addition, we discuss the accurateness of the results obtained in a full general relativistic approach in comparison with the ones obtained when the electric charge is assumed to be orbiting a massive object due to a Newtonian force.