Radiative Penrose process: Energy Gain by a Single Radiating Charged Particle in the Ergosphere of Rotating Black Hole

TL;DR

This paper demonstrates a novel energy extraction process from a rotating black hole using a single radiating charged particle within the ergosphere, which could be observable and relevant to astrophysical phenomena.

Contribution

It introduces the Radiative Penrose process, a new mechanism for energy gain that does not require particle interactions, expanding understanding of black hole energy extraction.

Findings

Charged particle can gain energy exceeding initial energy after radiating inside the ergosphere.

Energy of emitted radiation can be negative relative to a distant observer, enabling energy extraction.

The process may be relevant for astrophysical phenomena like jet formation.

Abstract

We demonstrate an extraordinary effect of energy gain by a single radiating charged particle inside the ergosphere of a Kerr black hole in presence of magnetic field. We solve numerically the covariant form of the Lorentz-Dirac equation reduced from the DeWitt-Brehme equation and analyze energy evolution of the radiating charged particle inside the ergosphere, where the energy of emitted radiation can be negative with respect to a distant observer in dependence on the relative orientation of the magnetic field, black hole spin and the direction of the charged particle motion. Consequently, the charged particle can leave the ergosphere with energy greater than initial in expense of black hole's rotational energy. In contrast to the original Penrose process and its various modification, the new process does not require the interactions (collisions or decay) with other particles and consequent restrictions on the relative velocities between fragments. We show that such a Radiative Penrose effect is potentially observable and discuss its possible relevance in formation of relativistic jets and in similar high-energy astrophysical settings.