Related papers: Maximum efficiency of the collisional Penrose proc…
Let a particle move in the flat space-time under the action of the electric potential. If it decays to two fragments, the energy of debris can be larger than the original energy and, moreover, the efficiency of such a process can be…
We consider collision of two particles near static electrically charged extremal black holes and elucidate the conditions under which the energy in the centre of mass frame E_{c.m.} grows unbounded. For a single black hole, we generalize…
We study the collision of two massive particles with non-zero intrinsic spin moving in the equatorial plane in the background of a Schwarzschild black hole surrounded by quintessential matter field (SBHQ). For the quintessential matter…
In the case involving particles the necessary and sufficient condition for the Penrose process to extract energy from a rotating black hole is absorption of particles with negative energies and angular momenta. No torque at the black-hole…
We study the collision of two particles with equal masses moving in the equatorial plane near horizon of the rotating regular Ay\'on-Beato-Garc\'ia (ABG) black hole (BH) and calculate the center-of-mass (CM) energy for the colliding…
If a supermassive black hole has some material orbiting around it at close to its innermost stable circular orbit (ISCO), then, when it plunges into a second supermassive black hole, the orbiting material has a velocity dispersion of order…
We consider generic rotating axially symmetric "dirty" (surrounded by matter) black holes. Near-horizon circular equatorial orbits are examined in two different cases of near-extremal (small surface gravity $\kappa $) and exactly extremal…
In this paper, we consider a well-established magnetic Penrose process (MPP) and bring out its impact on the efficiency of energy extraction from higher dimensional (i.e., $D>4$) black holes. We derive the field equations of motion and…
We investigate the extraction of rotational energy from rotating Einstein-Born-Infeld (EBI) black holes, where nonlinear electrodynamics introduces a radius-dependent effective charge modifying the spacetime geometry. Focusing on neutral…
The present study investigates the negative energy orbits and energy extraction efficiency using the magnetic Penrose process in various regular black hole geometries surrounded by electromagnetic fields. Utilizing numerical simulations, we…
We investigate here the issue of observability of high energy collisions around Kerr naked singu- larity and show that the results are in contrast with the Kerr black hole case. We had shown earlier that it would be possible to have…
The particle dynamics and the electric Penrose process for the five-dimensional weakly charged Schwarzschild black hole are studied. Firstly, the horizon structure and the effective potential for the test particle are explored. The radial…
Observations suggest that relativistic particles play a fundamental role in the dynamics of jets emerging from active galactic nuclei as well as in their interaction with the intracluster medium. However, no general consensus exists…
The rotating regular Hayward's spacetime, apart from mass ($M$) and angular momentum ($a$), has an additional deviation parameter ($g$) due to the magnetic charge, which generalizes the Kerr black hole when $g\neq0$, and for $g=0$, it goes…
The motion of classical spinning test particles in the equatorial plane of a Kerr black hole is considered for the case where the particle spin is perpendicular to the equatorial plane. We review some results of our recent research of the…
When two particles collide at the horizon of a black hole and one of them satisfies some critical conditions, the relative velocity between them can be arbitrarily large, thus the energy of the center-of-mass will reach infinity. Such a…
Magnetic Penrose process (MPP) could be highly efficient (efficiency can even exceed $100\%$) for extracting the energy from a Kerr black hole, if it is immersed in a mG order magnetic field. Considering the exact solution of the magnetized…
We study the possibility of obtaining unbound energy E_{c.m.} in the centre of mass frame when two particles collide near the inner black hole horizon. We consider two different cases - when both particles move (i) in the same direction or…
Results from general relativistic theoretical Monte Carlo computer simulations of Compton scattering and e-e+ pair production processes in the ergosphere of a supermassive (10^8 solar mass) rotating black hole are presented. Particles from…
Extracting the rotational energy from a Kerr black hole (BH) is one of the crucial topics in relativistic astrophysics. Here, we give special attention to the Penrose ballistic process based on the fission of a massive particle $\mu_0$ into…