High efficiency of the Penrose process of energy extraction from rotating black holes immersed in electromagnetic fields

Abstract

The conditions are analyzed under which maximum efficiency is obtained for the Penrose process (PP) of energy extraction from rotating black holes immersed in electromagnetic fields. The components of the dipole magnetic field are displayed superposed on the background Kerr metric as a representative case. Mathematical methods for analyzing the disintegrational PP are developed, obtaining an equation to a mass-hyperbola defined by mass parameters of fragments resulting from the disintegration of a particle incident on the black hole. The efficiency of the PP is considered, analyzing all the factors contributing toward high efficiency along with the plausible astrophysical limits. In particular, it is shown that the incident particle splitting near the static limit of the Kerr geometry gives an efficiency from which 100 percent energy extraction efficiency can be assumed in constructing the PP-based model of the central engine in AGNs. Finally, the use of these techniques in modeling AGNs is discussed.