Related papers: Rotating Charged Cylindrical Black Holes as Partic…
High-energy collisions can occur for radially moving charged test particles in the extremal Reissner-Nordstr\"om spacetime if one of the particles is fine-tuned and the collision point is taken close to the horizon. This is an analogy of…
Following the interesting work of Ba\~nados, Silk, and West [Phys. Rev. Lett. {\bf 103}, 111102 (2009)], it is repeatedly stated in the physics literature that the center-of-mass energy, ${\cal E}_{\text{c.m}}$, of two colliding particles…
When a particle moves around a Kerr black hole, it radiates gravitational waves.Some of these waves are absorbed by the black hole. We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on…
Similar to particle accelerators, black holes also have the ability to accelerate particles, generating significant amounts of energy through particle collisions. In this study, we examine the horizon and spacetime structures of a rotating…
We derive a general formula for the center-of-mass (CM) energy for the near-horizon collision of two particles of the same rest mass on the equatorial plane around a Kerr black hole. We then apply this formula to a particle which plunges…
In the teleparallel equivalent of general relativity the energy density of asymptotically flat gravitational fields can be naturaly defined as a scalar density restricted to a three-dimensional spacelike hypersurface $\Sigma$. Integration…
The most general electrically and magnetically charged rotating black hole solutions of 5 dimensional \KK\ theory are given in an explicit form. Various classical quantities associated with the black holes are derived. In particular, one…
According to Penrose effect, particles with negative energy can exist in the ergospheres of rotating black holes. We analyze geodesics for such particles and show that there are no circular and elliptic orbits in the ergosphere of a…
The rotating Ay\'{o}n-Beato-Garc\'{i}a (ABG) black holes, apart from mass ($M$) and rotation parameter ($a$), has an additional charge $Q$ and encompassed the Kerr black hole as particular case when $Q=0$. We demonstrate the ergoregions of…
A scalar field gravitational analog of the Reissner-Nordstrom solution is investigated. The nonlinear Newtonian model has an upper-limit of charge for a central mass which agrees with the general relativistic condition required for the…
We are motivated by the recently reported dynamical evidence of stars with short orbital periods moving around the center of the Milky Way and the corresponding hypothesis about the existence of a supermassive black hole hosted at its…
The origin of jets emitted from black holes is not well understood, however there are two possible energy sources, the accretion disk or the rotating black hole. Magnetohydrodynamic simulations show a well-defined jet that extracts energy…
Combined influence of rotation of a black hole and ambient magnetic fields creates conditions for powerful astrophysical processes of accretion and outflow of matter which are observed in many systems across the range of masses; from…
We investigate the horizon structure and ergosphere in a rotating Bardeen regular black hole, which has an additional parameter ($g$) due to magnetic charge, apart from mass ($M$) and rotation parameter ($a$). Interestingly, for each value…
We present a family of new rotating black hole solutions to Einstein's equations that generalizes the Kerr-Newman spacetime to include an anisotropic matter. The geometry is obtained by employing the Newman-Janis algorithm. In addition to…
The ability of a plasma surrounding spinning black holes to extract rotational energy and power energetic emissions has been recognized as a key astrophysical phenomenon. Important insights into the nature of this process are obtained…
The highest efficiency of converting rest mass into energy by accreting matter into a Kerr black hole is ~ 31% (Thorne 1974). We propose a new process in which periods of accretion from a thin disk, and the associated spin-up of the black…
Extreme-mass-ratio inspirals, in which a stellar-mass object orbits a supermassive black hole, are prime sources of millihertz gravitational waves for upcoming space-based detectors. While most studies assume idealized vacuum backgrounds,…
Radiation from a narrow circular ring shows a characteristic double-horn profile dominated by photons having energy around the maximum or minimum of the allowed range, i.e. near the extremal values of the energy shift. The energy span of a…
We consider collision of two geodesic particles moving around rotating stationary axially symmetric black holes. It is shown for arbitrary nonequatorial motion that under certain conditions the energy in their centre of mass frame can grow…