Related papers: Super-Penrose process for extremal rotating neutra…
A natural combined model of the Kerr spinning particle and superparticle is obtained leading to a non-trivial super black hole solution. By analogue with complex structure of the Kerr solution we perform a supershift on the Kerr geometry,…
We analyze the collisional Penrose process between a particle on the ISCO orbit around an extreme Kerr black hole and a particle impinging from infinity. We consider both cases with non-spinning and spinning particles. We evaluate the…
If two particles collide near the black hole horizon, the energy in the centre of mass (CM) frame can grow indefinitely (the so-called the BSW effect). This requires fine-tuning the parameters (the energy, angular momentum or electric…
It has recently been pointed out that, under certain conditions, the energy of particles accelerated by black holes in the center-of-mass frame can become arbitrarily high. In this paper, we study the collision of two particles in the case…
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 use a Monte Carlo code to calculate the geodesic orbits of test particles around Kerr black holes, generating a distribution function of both bound and unbound populations of dark matter particles. From this distribution function, we…
It is known that the center-of-mass energy of the collision of two massive particles following geodesics around a black hole presents a maximum. The maximum energy increases when the black hole is endowed with spin, and for a maximally…
This paper investigates the repetitive Penrose process in accelerating Kerr black holes and explores the influence of the acceleration factor on the repetitive Penrose process. After a brief review of accelerating Kerr black holes, we study…
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…
Recently, Ban\~{a}dos, Silk and West (BSW) demonstrated that the extremal Kerr black hole can act as a particle accelerator with arbitrarily high center-of-mass energy ($E_{CM}$) when the collision takes place near the horizon. The rotating…
Finite-energy particles in free fall can collide with diverging center-of-mass energy near rapidly rotating black holes. What are the most salient observational signatures of this remarkable geometric effect? Here we revisit the problem…
We show that any Lorentz violating theory with two or more propagation speeds is in conflict with the generalized second law of black hole thermodynamics. We do this by identifying a classical energy-extraction method, analogous to the…
We have developed a methodology to test the age-old cosmic censorship hypothesis in Kerr geometry. We have shown that the Kerr black hole can be overspun by particles captured from the innermost stable circular orbit. However, it appears…
Two particle collisions close to the horizon of the rotating nonextremal black hole are analyzed. It is shown that high energy of the order of the Grand Unification scale in the centre of mass of colliding particles can be obtained when…
We study collisions of many point-like particles in three-dimensional anti-de Sitter space, generalizing the known result with two particles. We show how to construct exact solutions corresponding to the formation of either a black hole or…
We show that effects similar to those for a rotating black hole arise for an observer using a uniformly rotating reference frame in a flat space-time: a surface appears such that no body can be stationary beyond this surface, while the…
The merger of two neutron stars will in general lead to the formation of a torus surrounding a black hole whose rotational energy can be tapped to potentially power a short gamma-ray burst. We have studied the merger of equal-mass binaries…
While theoretically established for decades, the Penrose process - energy extraction from rotating black holes - still lacks clear observational evidence. A promising theoretical framework posits magnetic reconnection in the ergosphere as a…
The collision of two particles in the background of a Sen black hole is studied. With the equations of motion of the particles, the center-of-mass energy is investigated when the collision takes place at the horizon of a Sen black hole. For…
We investigate how test particles absorbed by a black hole affect the properties of the event horizon. We consider particles that arrive from infinity with positive energy and cross the horizon. We also study the absorption of particles…