Related papers: Can matter really cross a horizon?
Black and white holes play remarkably contrasting roles in general relativity versus observational astrophysics. While there is overwhelming observational evidence for the existence of compact objects that are "cold, dark, and heavy", which…
Quantum gravity phenomenology suggests the interesting possibility that black holes are not eternal. Collapse could be halted by some unknown mechanism, or Hawking radiation might leave behind a regular spacetime. Here we investigate a…
In a shallow-water radial outflow the horizon of a hydrodynamic white hole coincides with a standing circular hydraulic jump. The jump, caused by viscosity, makes the horizon visible as a circular front, standing as a barrier against the…
The physical process version of the first law for black holes states that the passage of energy and angular momentum through the horizon results in a change in area $\frac{\kappa}{8 \pi} \Delta A = \Delta E - \Omega \Delta J$, so long as…
We present a robust mechanism where the geometrical free-gravitational entropy of an isolated astrophysical radiating star undergoing continual gravitational collapse, as measured by an external observer, makes a smooth transition to the…
In this paper, a natural generalization of KMY model is proposed for the evaporation of charged black holes. Within the proposed model, the back reaction of Hawking radiation is considered. More specifically, we consider the equation…
The black-hole information paradox has fueled a fascinating effort to reconcile the predictions of general relativity and those of quantum mechanics. Gravitational considerations teach us that black holes must trap everything that falls…
The gravitational collapse and the birth of a new universe are considered in terms of quantum mechanics. Transitions from annihilation of matter to deflation in the collapse and from inflation to creation of matter in the birth of a…
Following the Membrane Paradigm, we show that the stretched horizon of a black hole retains information about particles thrown into the hole for a time of order the scrambling time m ln(m/M_P), after the particles cross the horizon. One…
We prove that the black to white hole transition theorized in several papers can be described as a change in the topology of the event horizon. We also show, using the theory of cobordism due to Milnor and Wallace, how to obtain the full…
We first revisit Hartle and Hawking's path integral derivation of Hawking radiation. In the first point of view, we interpret that a particle-antiparticle pair is created and the negative energy antiparticle falls into the black hole. On…
The potentials of spin-weighted wave equations in various Kerr-Newman black holes are analyzed. They all form singular potential barriers at the event horizon. Applying the WKB approximation it is shown that no particle can tunnel out of…
We propose a classical solution for the kinetic description of matter falling into a black hole, which permits to evaluate both the kinetic entropy and the entropy production rate of classical infalling matter at the event horizon. The…
The Schwarzschild metric has an apparent singularity at the horizon r=2M. What really happens there? If physics at the horizon is 'normal' laboratory physics, then we run into Hawking's information paradox. If we want nontrivial structure…
We use the avoidance of the trans-Planckian problem of Hawking radiation as a guiding principle in searching for a compelling scenario for the evaporation of black holes or black-hole-like objects. We argue that there exist only three…
It is widely expected that generic black holes have a non-empty but weakly singular Cauchy horizon, due to mass inflation. Indeed this has been proven by the author in the spherical collapse of a charged scalar field, under decay…
We consider the effects of gravitons in the collapse of baryonic matter that forms a black hole. We first note that the effective number of (soft off-shell) gravitons that account for the (negative) Newtonian potential energy generated by…
We resolve the fate of the two original apparent horizons during the head-on merger of two non-spinning black holes. We show that following the appearance of the outer common horizon and subsequent inter-penetration of the original…
The introduction of coordinates representing the points of view of various observers results in the possibility of horizons when acceleration and gravitation are included. A horizon is a surface of possible light beams in a region of space…
We consider particle collision inside the inner horizon of the Reissner-Nordstrom metric in the so-called R region. We show that there exist scenario in which the enrgy in the center of mass frame grows unbounded. In contrast to the…