Related papers: Penrose Process in Kerr-Taub-NUT Spacetime
The Brown-York quasi-local energy of a rotating black hole described by the Kerr metric and enclosed by a fixed-radius surface is calculated by direct computation. No special assumptions on the angular momentum or the radial coordinate in…
In this paper we study the effects of the coupling constant of the Chern-Simons modified gravity on some physical properties of black holes. The Hawking mass is one of the proposed definitions of quasilocal mass. We find that, for slowly…
Superradiance is the effect of field waves being amplified during reflection from a charged or rotating black hole. In this paper, we study the low-energy dynamics of super-radiant scattering of massive scalar and massless higher spin field…
The energy extraction from an electrostatic black hole by the decay or splitting of electrically charged particles is analyzed. We determine the energetic conditions that make the extraction process viable and present a general expression…
During the three decades since its theoretical discovery the Blandford-Znajek process of extracting the rotational energy of black holes has become one of the foundation stones in the building of modern relativistic astrophysics. However,…
Recent work has called into question whether nature can extract the rotational energy of a black hole via electromagnetic fields by appealing to an alleged ability to absorb current. We describe the strategies needed to properly treat the…
We investigate the evaporation process of a Kerr-de Sitter black hole with the Unruh-Hawking-like vacuum state, which is a realistic vacuum state modelling the evaporation process of a black hole originating from gravitational collapse. We…
A new numerical method is introduced to study the problem of time evolution of generic non-linear dynamical systems in four-dimensional spacetimes. It is assumed that the time level surfaces are foliated by a one-parameter family of…
When a particle moves around a Kerr black hole, it radiates gravitational waves.Some of these waves are absorbed by the black hole. We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on…
We derive the exact form of effective potential in Kerr geometry from the general relativistic radial momentum equation. The effective potential accurately mimics the general relativistic features, over the entire range of the spin…
We consider the decay of a particle with some energy $E_{0}>0$ inside the ergosphere of a black hole. After the first decay one of particles with the energy $E_{1}<0$ falls towards a black hole while the second one with $% E_{2}>E_{0}\,\…
The exact mechanism by which astrophysical jets are formed is still unknown. It is believed that necessary elements are a rotating (Kerr) black hole and a magnetised accreting plasma. We model the accreting plasma as a collection of…
We present analytical expressions for the fluxes of energy and angular momentum from a point mass on an inclined spherical orbit about a Kerr black hole. The expressions are obtained using the method of Mano, Suzuki and Takasugi to…
This article focuses on the new approach to the nature of a nut parameter $n$, usually treated as a dual charge to the mass. Instead of thinking about it as a gravitational analog of the magnetic monopole, we will show that the Taub-NUT…
We study the properties of the relativistic, steady, axisymmetric, low angular momentum, inviscid, advective, geometrically thin accretion flow in a Kerr-Taub-NUT (KTN) spacetime which is characterized by the Kerr parameter ($a_{\rm k}$)…
Hawking evaporation of photons in a variable-mass Kerr space-time is investigated by using a method of the generalized tortoise coordinate transformation. The blackbody radiant spectrum of photons displays a new spin-rotation coupling…
A disformal rotating black-hole solution is a black-hole solution in quadratic degenerate higher-order scalar-tensor theories. It breaks the circular condition of spacetime different from the case of the usual Kerr spacetime. This study…
We consider collision of particles in a wormhole near its throat. Particles come from the opposite mouths. If the lapse function is small enough there, the energy $E$ of debris at infinity grows unbounded, so we are faced with the so-called…
The gravitational waves and energy radiations from a spinning compact object with stellar mass in a circular orbit in the equatorial plane of a supermassive Kerr black hole are investigated in this paper. The effect how the spin acts on…
The shadow of a rotating black hole with nonvanishing gravitomagnetic charge has been studied. It was shown that in addition to the angular momentum of black hole the gravitomagnetic charge term deforms the shape of the black hole shadow.…