Related papers: Post-radiation evolution of black holes
A black hole is the end state of the gravitational collapse of massive stars. However, a typical black hole contains a singularity and to avoid singularity formation we have to violate a strong energy condition that states that gravity must…
The potential behind the horizon of an eternal black hole in classical theories is described in terms of data that is available to an external observer -- the reflection coefficient of a wave that scatters on the black hole. In GR and…
The existence of extremely dark and compact astronomical bodies is by now a well established observational fact. On the other hand, classical General Relativity predicts the existence of black holes which fit very well with the…
Charged black holes are known to suffer from an interior instability associated with the presence of the Cauchy horizon. Recently, a hairy charged black hole was proposed that avoids the formation of a Cauchy horizon. It is natural to…
Trapped regions bounded by horizons are the defining features of black holes. However, formation of a singularity-free apparent horizon in finite time of a distant observer is consistent only with special states of geometry and matter in…
When a black hole accretes slowly, the radiative cooling of the infalling gas is weak and the accretion disk does not form. A hot collisionless quasi-spherical halo is formed instead. The properties of such halos are discussed. The rate of…
We model the collapse of a spherically symmetric, constant density, pressureless shell onto a preexisting black hole. Contrary to a recent claim of Liu and Zhang (2009), we show that an observer at infinity never sees any part of the shell…
We consider solutions to the linear wave equation on a (maximally extended) Schwarzschild spacetime, assuming only that the solution decays suitably at spatial infinity on a complete Cauchy hypersurface. (In particular, we allow the support…
Black holes are presumed to have an ideal ability to absorb and keep matter. Whatever comes close to the event horizon, a boundary separating the inside region of a black hole from the outside world, inevitably goes in and remains inside…
A simple argument is given that a traversable Cauchy horizon inside a black hole is incompatible with unitary black hole evolution. The argument assumes the validity of black hole complementarity and applies to a generic black hole carrying…
The electromagnetic radiation that falls into a Reissner-Nordstrom black hole develops a ``blue sheet'' of infinite energy density at the Cauchy horizon. We consider classical electromagnetic fields (that were produced during the collapse…
It has long been known that, in higher-dimensional general relativity, there are black hole solutions with an arbitrarily large angular momentum for a fixed mass. We examine the geometry of the event horizon of such ultra-spinning black…
An astrophysically realistic model of wave dynamics in black-hole spacetimes must involve a non-spherical background geometry with angular momentum. We consider the evolution of gravitational (and electromagnetic) perturbations in rotating…
We study the causal structure of dynamical charged black holes, with a sufficient number of massless fields, using numerical simulations. Neglecting Hawking radiation, the inner horizon is a null Cauchy horizon and a curvature singularity…
We investigate the interplaying effects of black hole scalarization and superradiance in the context of the Einstein-Maxwell-scalar model, with the scalar field possessing electric charge. Restricted to spherical symmetry, our linear…
Extending previous work on the formation and the evaporation of black holes in conformal gravity, in the present paper we study the gravitational collapse of a spherically symmetric and electrically charged thin shell of radiation. The…
The conservative model of a black hole is advanced. The model incorporates conservation laws such as those of baryon and lepton numbers, which lifts the information loss paradox. A scenario of black hole evaporation is considered. Keywords:…
We present a semi-classical model for the formation and evaporation of a four dimensional black hole. We solve the equations numerically and obtain solutions describing the entire the space-time geometry from the collapse to the end of the…
The shadow of a black hole is usually calculated, either analytically or numerically, on the assumption that the black hole is eternal, i.e., that it existed for all time. Here we ask the question of how this shadow comes about in the…
A simple, geometrical construction is given for three-dimensional spacetimes with negative cosmological constant that contain two particles colliding head-on. Depending on parameters like particle masses and distance, the combined geometry…