Related papers: Energy of 4-Dimensional Black Hole, etc
The dimensional reduction of black hole solutions in four-dimensional (4D) general relativity is performed and new 3D black hole solutions are obtained. Considering a 4D spacetime with one spacelike Killing vector, it is possible to split…
In this paper, we review the issue of defining energy for test particles on a background stationary spacetime. We revisit the different notions of energy as defined by different observers. As is well known, the existence of a time-like…
The energy of a test particle orbiting a Schwarzschild black hole is quantized owing to the quantization of the angular momentum. For smallest stable circular orbit, the excitation energy is found to resemble closely the expression for the…
Dilatations by means of a constant factor can be seen in a double way: as a simple change of units length or as a conformal mapping of the starting spacetime into a ``stretched'' one with the same units length. The numerical value of the…
Two particles can collide inside a nonextremal black hole in such a way that the energy E_{c.m.} in their centre of mass frame becomes as large as one likes. We show that this effect can be understood with the help of a simple analogy with…
What is the average density of a black hole, assuming its spin can prevent it from collapsing into a singularity? For stellar black holes, the average density is incredibly dense and has over a trillion G force and tidal force that will rip…
We investigate, in the case of a Reissner-Nordstr\"om black hole, the definitions of gravitational energy and gravitational pressure that naturally arise in the framework of the Teleparallel Equivalent of General Relativity. In particular,…
In this paper we consider charged rotating black hole in 3 dimensions with an scalar charge and discuss about energy loss of heavy particle moving near the black hole horizon. We also study quasi-normal modes and find dispersion relations.…
We reinterpret recent work on extremal Reissner- Nordstr\o m black holes to argue that the mass is a measure of the gravitational entropy. We also find that the entropy of scalar fields in this background has a stronger divergence than…
I report the discovery of a new effect of General Relativity which is important to understand very rapidly rotating (Kerr) black holes. The orbital velocity of a test particle is no longer a monotonic function of the orbit radius when the…
Using three different energy-momentum complexes, the Einstein, Landau-Lifshitz, and Papapetrou prescriptions, we calculate the energy of an electrically charged black hole exact solution with a self-interacting, minimally-coupled scalar…
We investigate various properties of extremal dyonic static black holes in Einstein-Maxwell-Dilaton-Axion theory. We obtain a simple first-order ordinary differential equation for the black hole mass in terms of its electric and magnetic…
This poster discusses a possible explanation for the relationship between the mass of the central supermassive black hole and the velocity dispersion in the bulge of the host galaxy. We suppose that the black hole and the dark matter halo…
To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$. This…
Using a simple analysis based on the measurement procedure for a quantized area we explain the 1/4 factor in the Bekenstein-Hawking black hole formula A/4 for the entropy.
It has been suggested that rotating black holes could serve as particle colliders with arbitrarily high center-of-mass energy. Astrophysical limitations on the maximal spin, back-reaction effects and sensitivity to the initial conditions…
In this paper we construct rotating charged hairy black hole in (2+1) dimensions for infinitesimal black hole charge and rotation parameters. Then we consider this black hole as particle accelerator and calculate the center-of-mass energy…
We provide a new regular black hole solution in $(2+1)$ dimensions with presence of matter fields in the energy momentum tensor, having its core a flat or (A)dS structure. Since the first law of thermodynamics for regular black holes is…
We investigate the dynamical behavior of phantom energy near stringy magnetically charged black hole. For this purpose, we derive equations of motion for steady-state spherically symmetric flow of phantom energy onto the stringy…
We calculate the gray-body factors for scalar, vector and graviton fields in the background of an exact black hole localized on a tensional 3-brane in a world with two large extra dimensions. Finite brane tension modifies the standard…