Speaker
Description
Finding efficient mechanisms for extracting the energy of Reissner-Nordström, Kerr, and Kerr-Newman black holes (BHs) is a most relevant astrophysical task, as they represent, in principle, the most significant energy sources in the universe. However, the increase in the BH irreducible mass limits the efficiency of any process. Quantifying how much the irreducible mass increases during an extraction process is therefore a key, although often overlooked, aspect in astrophysical applications. This talk quantifies the increase in the irreducible mass during energy-extraction processes in Reissner-Nordström and Kerr BHs, including the gravitational and electric Penrose processes, and charged-particle capture by a Kerr BH immersed in an external magnetic field. It discusses future directions of research in this area.