# Fifty years of energy extraction from rotating black hole: revisiting magnetic Penrose process

## TL;DR

This paper revisits the magnetic Penrose process, analyzing its physics across different efficiency regimes and its potential to power high-energy astrophysical phenomena like cosmic rays and jets, emphasizing its observational predictions.

## Contribution

It provides a comprehensive review of MPP physics in various regimes and compares it with other mechanisms, highlighting its astrophysical significance and observational implications.

## Key findings

- MPP can power ultra-high-energy cosmic rays and relativistic jets.
- Different regimes of MPP efficiency depend on black hole magnetization and charge.
- MPP offers observable predictions for high-energy astrophysical phenomena.

## Abstract

Magnetic Penrose process (MPP) is not only the most exciting and fascinating process mining the rotational energy of black hole but it is also the favored astrophysically viable mechanism for high energy sources and phenomena. It operates in three regimes of efficiency, namely low, moderate and ultra, depending on the magnetization and charging of spinning black holes in astrophysical setting. In this paper, we revisit MPP with a comprehensive discussion of its physics in different regimes, and compare its operation with other competing mechanisms. We show that MPP could in principle foot the bill for powering engine of such phenomena as ultra-high-energy cosmic rays, relativistic jets, fast radio bursts, quasars, AGNs, etc. Further, it also leads to a number of important observable predictions. All this beautifully bears out the promise of a new vista of energy powerhouse heralded by Roger Penrose half a century ago through this process, and it has today risen in its magnetically empowered version of mid 1980s from a purely thought experiment of academic interest to a realistic powering mechanism for various high-energy astrophysical phenomena.