Related papers: Rapidly rotating spacetimes and collisional super-…
We consider collisional Penrose process for charged, rotating black holes together with a simple model of pair creation, in which two oppositely charged particles are produced in a collision of two neutral particles. We highlight that…
The BSW effect implies that the energy $E_{c.m.}$ in the center of mass frame of two particles colliding near a black hole can become unbounded. Usually, it is assumed that particles move along geodesics or electrogeodesics. Instead, we…
We study the collision property of spinning particles near a Ba\~nados-Teitelboim-Zanelli (BTZ) black hole. Our results show that although the center-of-mass energy of two ingoing particles diverges if one of the particles possesses a…
Rapidly rotating Kerr black holes can accelerate particles to arbitrarily high energy if the angular momentum of the particle is fine-tuned to some critical value. This phenomenon is robust as it is founded on the basic properties of…
We studied the magnetic Penrose process (MPP) in the Kerr-Bertotti-Robinson (KBR) spacetime, an exact rotating electrovacuum solution describing a black hole (BH) immersed in an intrinsic, uniform electromagnetic field. We analyze the…
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 study the scenario in which a massive particle is thrown into a rapidly rotating Kerr black hole in an attempt to spin it up beyond its extremal limit, challenging weak cosmic censorship. We work in black-hole perturbation theory, and…
We argue that the possibility of having infinite energy in the centre of mass frame of colliding particles is a generic property of rotating black holes. We suggest a general model-independent derivation valid for "dirty" black holes. The…
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…
We show that collisions between particles free falling from infinity and a disk of material plunging off the retrograde innermost stable circular orbit of a near-extremal Kerr black hole is the unique astronomically natural way in which to…
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…
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 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…
In many astrophysical scenarios the charge of the black hole is often neglected due to unrealistically large values of the charge required for the Reissner-Nordstr\"om spacetime metric. However, black holes may possess small electric charge…
Recently, Ban\~{a}dos, Silk and West (BSW) found that the center-of-mass energy of two colliding test particles in the neighborhood of an extreme Kerr black hole could be arbitrarily high when one particle has the critical angular momentum…
We obtain an explicit expression for the center-of-mass (CM) energy of two colliding general geodesic massive and massless particles at any spacetime point around a Kerr black hole. Applying this, we show that the CM energy can be…
We analyze the properties of the circular orbits for massive particles in the equatorial plane of symmetric rotating Ellis wormholes. In particular, we obtain the orbital frequencies and the radial and vertical epicyclic frequencies, and…
We consider the problem of gravitational deflection of a propagating relativistic massive particles by rotating black holes (Kerr black holes) and rotating wormholes (Teo wormholes) in the weak limit approximation. In particular we have…
Recently, references [1,2] found that the repetitive Penrose process cannot extract all the extractable rotational energy of a Kerr black hole, and reference [3] found that the repetitive electric Penrose process cannot extract all the…
Two particles can collide in the vicinity of a rotating black hole producing the divergent energy in the centre of mass frame (the BSW effect). However, it was shown recently that an observer at infinity can register quite modest energies E…