Related papers: The Membrane Paradigm and Firewalls
The so-called memory-burden effect implies that evaporating Primordial Black Holes (PBHs) inevitably stabilize before complete decay. This stabilization opens a new mass window for PBH Dark Matter below $10^{15}\,$g. The transition to the…
The quantum field theory for a massless scalar field on a two-dimensional non-singular black hole spacetime gives a non-vanishing probability for a particle to tunnel out of the black hole. The black hole spacetime contains an outer and an…
In this paper we argue that a firewall is simply a manifestation of an inconsistent truncation of non-perturbative effects that unitarize the semiclassical black hole. Namely, we show that a naive truncation of quantum corrections to the…
Unitarity implies that the evaporation of microscopic quasi-classical black holes cannot be universal in different particle species. This creates a puzzle, since it conflicts with the thermal nature of quasi-classical black holes, according…
I review elements of the foundations of black-hole theory with attention to problematic issues, and describe some techniques which either seem to help with the difficulties or at least investigate their scope. The definition of black holes…
Quantum entanglement of Hawking radiation has been supposed to give rise to a Planck density "firewall" near the event horizon of old black holes. We show that Planck density firewalls are excluded by Einstein's equations for black holes of…
BMN Matrix theory admits vacua in the shape of large spherical membranes. Per- turbing around such vacua, the setup provides for a controlled computational frame- work for testing information evolution in Matrix black holes. The theory…
Two seemingly distinct notions regarding black holes have captured the imagination of theoretical physicists over the past decade: First, black holes are conjectured to be fast scramblers of information, a notion that is further supported…
We study a black hole of mass $M$, enclosed within a spherical box, in equilibrium with its Hawking radiation. We show that the spacetime geometry inside the box is described by the Oppenheimer-Volkoff equations for radiation, except for a…
A semi-classical reasoning leads to the non-commutativity of the space and time coordinates near the horizon of Schwarzschild black hole. This non-commutativity in turn provides a mechanism to interpret the brick wall thickness hypothesis…
The black hole information paradox is a very poorly understood problem. It is often believed that Hawking's argument is not precisely formulated, and a more careful accounting of naturally occurring quantum corrections will allow the…
Quantum fluctuations in the background geometry of a black hole are shown to affect the propagation of matter states falling into the black hole in a foliation that corresponds to observations purely outside the horizon. A state that starts…
The boundary of any observer's spacetime is the boundary that divides what the observer can see from what they cannot see. The boundary of an observer's spacetime in the presence of a black hole is not the true (future event) horizon of the…
We resolve black hole information paradox within semiclassical gravity, in a manner that does not depend on details of unknown quantum gravity. Our crucial insight is that outgoing Hawking particles are physical only far from the black hole…
We investigate the consequences for the black hole area of introducing fractal structure for the horizon geometry. We create a three-dimensional spherical analogue of a 'Koch Snowflake' using a infinite diminishing hierarchy of touching…
We study analytically the spacetime geometry of the black-hole formation and evaporation. As a simplest model of the collapse, we consider a spherical thin shell, and take the back-reaction from the negative energy of the quantum vacuum…
Recently we pointed out that the black hole interior operators can be reconstructed by using the Hayden-Preskill recovery protocols. Building on this observation, we propose a resolution of the firewall problem by presenting a…
It has been taken as a truth that collapsing matter can eventually cross the horizon and enter into the interior of a black hole in a finite proper time. However, the Rindler/tachyon dual description we suggest recently implies that this…
In the context of a two-dimensional exactly solvable model, the dynamics of quantum black holes is obtained by analytically continuing the description of the regime where no black hole is formed. The resulting spectrum of outgoing radiation…
We embed an object with a singular horizon structure, reminiscent of (but fundamentally different from, except in a limiting case) a black-hole event horizon, in an expanding, spherically symmetric, homogeneous, Universe that has a positive…