Astrophysical black hole candidates, although long thought to have a horizon, could be
horizonless ultracompact objects. This intriguing possibility is motivated by the black hole …

We consider accretion of charged test matter by rotating, magnetic black holes and discuss a
number of aspects in which the interaction of the angular momentum contained in the …

Shortly after the discovery of the Kerr metric in 1963, it was realized that a region existed
outside of the black hole's event horizon where no time-like observer could remain …

We investigate the dynamics of a neutral and a charged particle around a black hole in
modified gravity immersed in a magnetic field. Our focus is on the scalar-tensor-vector theory …

We study here the precession of the spin of a test gyroscope attached to a stationary
observer in the Kerr spacetime, specifically, to distinguish a naked singularity (NS) from a …

Soon after the discovery of the Kerr metric, Penrose realized that superradiance can be
exploited to extract energy from black holes. The original idea (involving the breakup of a …

We demonstrate that the rotating four-dimensional Gauss–Bonnet black hole can act as a
particle accelerator with arbitrarily high centre-of-mass (CM) energy, when collision of two …

The Penrose process for the decay of electrically charged particles in a Reissner-Nordström-
anti–de Sitter black hole spacetime is studied. To extract large quantities of energy one …

A bstract Recently, Bañados, Silk and West (BSW) demonstrated that the extremal Kerr black
hole can act as a particle accelerator with arbitrarily high center-of-mass energy (E CM) …

The latest findings of static and spherically symmetric black hole solution give a potential
platform to investigate the novel four-dimensional Einstein Gauss–Bonnet gravity. In order to …