Related papers: Implementing black hole as efficient power plant
We performed simulations of collapsars with different Kerr parameters a=0, 0.5, 0.9, 0.95. It is shown that a more rapidly rotating black hole is driving a more energetic jet. No jet is seen for the case of Schwartzschild black hole case,…
Recently, there has been a surge of interest in the 4D Einstein-Gauss-Bonnet (4D EGB) gravity theory which bypasses the Lovelock theorem and avoids Ostrogradsky's instability. Such a novel theory has nontrivial dynamics and presents several…
We investigate the possibility of computing energy by means of operators associated to the Wheeler-DeWitt equation. By choosing three dimensional wormholes as a framework, we apply such calculation scheme to the black hole pair creation. We…
This study explores the thermodynamic and geometric properties of phantom BTZ black holes within a noncommutative spacetime framework, where noncommutativity is implemented through Lorentzian smearing of mass and charge distributions. The…
Scattering of particles in the gravitational field of rotating black holes is considered. It is shown that scattering energy of particles in the centre of mass system can obtain very large values not only for extremal black holes but also…
We propose a novel method to constrain the electric charge of the supermassive black hole M87* by analyzing the orbital angular momentum content of the light it emits. By leveraging the established analogy between rotating spacetimes and…
Horizon fluxes of energy and angular momentum are a key strong-field effect in the dynamics of black holes, encoding direct information about their nature. In this work, we present a numerical study of these fluxes for a test particle…
We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried…
An introduction is given to a meeting on the role of massive and stellar black holes in powering non-thermal activity in a rich variety of cosmic sources. Relevant properties of magnetized, spinning black holes are summarized and their…
In the context of black hole chemistry, we study the thermodynamics of asymptotically de Sitter black holes with conformal scalar hair in Einstein gravity. The hair parameter allows us to attain thermodynamic equilibrium between the event…
We investigate the charging performance of a quantum battery coupled to a scalar field in the background of a three-dimensional rotating black hole. We show that for Dirichlet boundary conditions, the black hole rotation enhances the…
We derive a singular solution for the rotating counterpart of Lee-Wick gravity having a point source in a higher-derivative theory. We critically analyze the thermodynamics of such a thermal system by evaluating mass parameters, angular…
The Bronnikov model of nonlinear electrodynamics is investigated in general relativity. The magnetic black hole is considered and we obtain a solution giving corrections to the Reissner-Nordstr\"{o}m solution. In this model spacetime at…
We consider the Blandford-Znajek (BZ) mechanism for extracting black hole spin energy to drive astrophysical jets. Analyses of the BZ mechanism generally take no account of any electric charge on the black hole. But, as noted by Wald and…
We investigate the thermodynamics of a general class of exact 4-dimensional asymptotically Anti-de Sitter hairy black hole solutions and show that, for a fixed temperature, there are small and large hairy black holes similar to the…
From the black hole thermodynamics point of view, we show that the entropy function $\mathbf{f}$ and the free energy $F$ are related via $\mathbf{f}=e_{I}q_{I}+\Omega_Hq_I{A_{\phi}^I}'-\frac{\partial F}{\partial r} |_{r_{H}}$. Assuming the…
In this article, we study the circular motion of particles and the well-known Penrose mechanism around a Kerr-Newman-Kasuya black hole spacetime. The inner and outer horizons, as well as ergosurfaces of the said black hole, are briefly…
In two-derivative theories of gravity coupled to matter, charged black holes are self-attractive at large distances, with the force vanishing at zero temperature. However, in the presence of massless scalar fields and four-derivative…
A small black hole attached to a brane in a higher dimensional space emitting quanta into the bulk may leave the brane as a result of a recoil. We construct a field theory model in which such a black hole is described as a massive scalar…
Accreting black holes can release enormous amounts of energy to their surroundings, in various forms. Such feedback may profoundly influence a black hole's environment. After briefly reviewing the possible types of feedback, I focus on the…