Related papers: Can matter really cross a horizon?
We examine a possibility that, when a black hole is formed, the information on the collapsed star is stored as the entanglement entropy between the outside and the thin region (of the order of the Planck length) of the inside the horizon.…
The concept of a horizon known from general relativity describes the loss of causal connection and can be applied to non-gravitational scenarios such as out-of-equilibrium condensed-matter systems in the laboratory. This analogy facilitates…
Basic properties of black holes are explained in terms of trapping horizons. It is shown that matter and information will escape from an evaporating black hole. A general scenario is outlined whereby a black hole evaporates completely…
We investigate the effect of gravitational back-reaction on the black hole evaporation process. The standard derivation of Hawking radiation is re-examined and extended by including gravitational interactions between the infalling matter…
We study the possibility of obtaining unbound energy E_{c.m.} in the centre of mass frame when two particles collide near the inner black hole horizon. We consider two different cases - when both particles move (i) in the same direction or…
We construct a self-consistent model which describes a black hole from formation to evaporation including the back reaction from the Hawking radiation. In the case where a null shell collapses, at the beginning the evaporation occurs, but…
In calculations of gravitational collapse to form black holes, trapping horizons (foliated by marginally trapped surfaces) make their first appearance either within the collapsing matter or where it joins on to a vacuum exterior. Those…
Oppenheimer and Snyder found in 1939 that gravitational collapse in vacuum produces a "frozen star", i.e., the collapsing matter only asymptotically approaches the gravitational radius (event horizon) of the mass, but never crosses it…
It has been well known that in the point of view of a distant observer, all in-falling matter to a black hole (BH) will be eventually stalled and "frozen" just outside the event horizon of the BH, although an in-falling observer will see…
The requirement that a trapped spacetime domain forms in finite time for distant observers is logically possible and sometimes unavoidable, but its consequences are not yet fully understood. In spherical symmetry, the characterization of…
The gravitational collapse of a pressureless fluid in general relativity (Oppenheimer-Snyder collapse) results in a black hole. The study of the same phenomenon in the brane-world scenario has shown that the exterior of the collapsing dust…
We present a static solution for $d = 2$ critical string theory including the tachyon $T$ but not its potential $V(T)$. This solution thus incorporates tachyon back reaction and, when $T = 0$, reduces to the black hole solution. When $T…
We discuss and compare definitions of a black hole based on the existence of event and apparent horizons. In this connection we present a non-singular model of a black hole with a closed apparent horizon and discuss its properties. We…
String theory tells us that quantum gravity has a dual description as a field theory (without gravity). We use the field theory dual to ask what happens to an object as it falls into the simplest black hole: the 2-charge extremal hole. In…
When a black hole forms from collapse in a holographic theory, the information in the black hole interior remains encoded in the boundary. We prove that the area of the black hole's apparent horizon is precisely the entropy associated 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…
In recent years the threshold of black hole formation in spherically symmetric gravitational collapse has been studied for a variety of matter models. In this paper the corresponding issue is investigated for a matter model significantly…
Along with compacting baryon (neutron) spacing, two very important factors come into play at once: the lack of self-stabilization within a compact neutron star (NS) associated with possible black hole (BH) horizon appearance and the phase…
The relation between event horizons and trapping horizons is investigated in a number of different situations with emphasis on their role in thermodynamics. A notion of constant change is introduced that in certain situations allows the…
Understood in terms of pure states evolving into mixed states, the possibility of information loss in black holes is closely related to the global causal structure of spacetime, as is the existence of event horizons. However, black holes…