An exact charged axially symmetric solution of the coupled gravitational and electromagnetic fields in the teleparallel equivalent of Einstein theory is derived. It is characterized by three parameters " the gravitational mass M, the charge parameter Q and the rotation parameter a " and its associated metric gives Kerr-Newman spacetime. The parallel vector field and the electromagnetic vector p...

It is shown that the description of collapse given by the classic model of Oppenheimer and Snyder fails to satisfy a crucial matching condition at the surface of the ball. After correcting the model so that the interior and exterior metrics match correctly, it is established that the contraction process stops at the Schwarzschild radius, that there is an accumulation of particles at the surface...

In this paper we show that the entropy of a cosmological horizon in topological Reissner-Nordström-de Sitter and Kerr-Newman-de Sitter spaces can be described by the Cardy-Verlinde formula, which is supposed to be an entropy formula of conformal field theory in any number of dimension. Furthermore, we find that the entropy of a black hole horizon can also be rewritten in terms of the Cardy-Verl...

(1) Ideal general relativistic MHD (ideal GRMHD) simulation: Jet formation by magnetic bridges between the ergosphere and disk around a rapidly black hole: Anti-parallel magnetic field ⇒ Magnetic reconnection (2) GRMHD with finite conductivity (σGRMHD): Numerical method and simple tests

Propagation of a fermion in curved space-time generates a gravitational interaction due to coupling of its spin with the space-time curvature connection. This gravitational interaction, which is an axialfour-vector multiplied by a four gravitational vector potential, appears as a CPT violating term in the Lagrangian which generates an opposite sign and thus asymmetry between the left-handed and...

In this Letter we consider the radial infall along the symmetry axis of an ultra-relativistic point particle into a rotating Kerr black hole. We use the Sasaki-Nakamura formalism to compute the waveform, energy spectra and total energy radiated during this process. We discuss possible connections between these results and the black holeblack hole collision at the speed of light process.

There are three regimes of gravitational-radiation-reaction-induced inspiral for a compact body with mass m , in a circular, equatorial orbit around a Kerr black hole with mass M@m: ~i! the adiabatic inspiral regime, in which the body gradually descends through a sequence of circular, geodesic orbits; ~ii! a transition regime, near the innermost stable circular orbit ~isco!; ~iii! the plunge re...

We show that using an adequate coordinate transformation the charged regular black hole solution given by Ayón-Beato and Garcia can be put in the Kerr-Schild form. Then we use this metric in Kerr-Schild Cartesian coordinates with a result given by Virbhadra and obtain the energy distribution associated with this.

Quasi-spherical light cones are lightlike hypersurfaces of the Kerr geometry that are asymptotic to Minkowski light cones at infinity. We develop the equations of these surfaces and examine their properties. In particular, we show that they are free of caustics for all positive values of the Kerr radial coordinate r. Useful applications include the propagation of high-frequency waves, the defin...