Rotating charged black holes in Kalb–Ramond gravity: electromagnetic fields, circular motion and collisions of charged particles

Abstract In this study, we investigate the electromagnetic field properties of a rotating charged black hole (BH) within the Kalb–Ramond gravity, as well as the circular motion and collisions of test charged particles in the spacetime of the BH. First, the static solutions of the Kalb–Ramond BH are derived using modified Einstein field equations and Maxwell’s equations to obtain the anisotropic solutions of the charged Kalb–Ramond BH. Then, using the Janis–Newman formalism, the exact solutions of the rotating Kalb–Ramond BH are obtained from the static metric. Subsequently, we investigate the horizon properties of the resulting rotating BH. It is shown that all the BH parameters charge and rotation, together with the Kalb–Ramond field, cause the horizon to extend, thereby providing additional gravitational mass. Then, we derive expressions for non-zero components of electromagnetic field configurations with respect to a zero angular momentum observer around the BHs. We also explore the circular motion of charged test particles, determining their effective potential and innermost stable circular orbits (ISCOs), which are influenced by the interplay of gravitational, rotational, and electromagnetic forces. Furthermore, we examine high-energy collisions of charged particles near the event horizon, computing the center-of-mass energy and demonstrating its enhancement by the Kalb–Ramond parameter and BH charge. Our results highlight the potential of charged rotating Kalb–Ramond BHs as natural particle accelerators, offering insights into extreme gravitational and electromagnetic phenomena with implications for astrophysics and theoretical physics.