相关论文: Overspinning BTZ black holes with test particles a…
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…
Evidences have been found that the weak cosmic censorship conjecture could be violated if test particles with charge and angular momentum are injected into a black hole. However, second-order corrections and fine-tunings on the particle's…
By neglecting the self-force, self-energy, and radiative effects, it has been shown that an extremal or near-extremal Kerr-Newman black hole can turn into a naked singularity when it captures charged and spinning massive particles. A…
The Weak Gravity Conjecture arises from the assertion that all extremal black holes, even those which are "classical" in the sense of being very massive, must decay by quantum-mechanical emission of particles or smaller black holes. This is…
Superradiance is a process by which massive bosonic particles can extract energy from spinning black holes, leading to the build up of a "cloud" if the particle has a Compton wavelength comparable to the black hole's Schwarzschild radius.…
Arguments are given for the conclusion that the energy of collision of two ultrarelativistic elementary particles due to gravitational radiation cannot exceed the Planck value. Comparison of the gravitational and electromagnetic radiation…
The new version of the gedanken experiment proposed by Sorce and Wald has been used to examine the weak cosmic censorship conjecture (WCCC) for black holes at the second-order approximation of the matter fields perturbation. However, only…
Black hole superradiance is a powerful probe of light, weakly-coupled hidden sector particles. Many candidate particles, such as axions, generically have self-interactions that can influence the evolution of the superradiant instability. As…
It has been recently observed that a scalar field with Robin boundary conditions (RBCs) can trigger both a superradiant and a bulk instability for a BTZ black hole (BH). To understand the generality and scrutinize the origin of this…
Hawking radiation acts as a cosmic censor since it carries away the angular momentum of the black hole, proportionally more than its mass. In this work we first show that an extremal black hole cannot exist since it will be pushed away from…
We investigate effect of a test magnetic field on the process of destroying near-extremal Kerr black hole with a charged test particle. It has been shown that it would be possible to throw a charged test particle into the near extremal…
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…
Beam powers and black hole masses of 48 extended radio sources are combined to obtain lower bounds on the spins and magnetic field strengths of supermassive black holes. This is done in the context of the models of Blandford & Znajek (1977)…
We investigate the weak cosmic censorship conjecture in Kerr-(anti-)de Sitter black holes under the scattering of a scalar field. We test the conjecture in terms of whether the black hole can exceed the extremal condition with respect to…
We study the collision between a BTZ black hole and a test particle coupled to a scalar field. We compute the power spectrum, the energy radiated and the plunging waveforms for this process. We show that for late times the signal is…
Accelerating black holes have been widely studied in the context of black hole thermodynamics, holographic gravity theories, and in the description of black holes at the center of galaxies. As a fundamental assumption to ensure spacetime…
We consider particle collisions in the background of a nonextremal black hole. Two particles fall from infinity, particle 1 is fine-tuned (critical), collision occurs in its turning point. The first example is the Reissner-Nordstr\"{o}m…
If astrophysical black hole candidates are the Kerr black holes predicted by General Relativity, the value of their spin parameter must be subject to the theoretical bound $|a_*| \le 1$. In this work, we consider the possibility that these…
We examine the problem of overcharging extremal and near-extremal black hole solutions of Einstein-Gauss-Bonnet gravity in any dimension, generalizing the result in general relativity. We show that as in the case of general relativity, it…
Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect.…