Penrose process and energy extraction efficiency in rotating Einstein-Born-Infeld black holes

Abstract In this paper, we have investigated the rotational energy extraction from rotating Einstein–Born–Infeld (EBI) black holes in the presence of nonlinear electrodynamics. Analytical expressions for the dynamics of test particles are obtained, and the conditions for negative-energy trajectories associated with the Penrose process are derived using the near-horizon approximation and the Wald inequality. A closed-form expression for the maximum extraction efficiency is determined in terms of the black hole spin, electric charge, and the Born–Infeld (BI) parameter β . Our results show that the electric charge and BI parameter affect the horizon and ergoregion. These changes also influence the Penrose efficiency and the allowed black-hole parameter range. The irreducible mass is also examined, indicating that nonlinear electromagnetic effects decrease the horizon area and the associated entropy. In the weakly nonlinear regime, the EBI results smoothly approach the Kerr–Newman limit. The present work establishes a quantitative framework for analyzing how nonlinear electrodynamics modify ergoregion structure and the Penrose energy extraction process in rotating BI black hole spacetimes.