Related papers: Black Holes and the Scientific Process
The black hole information paradox is among the most outstanding puzzles in physics. I argue here there is yet another black hole quandary which, in light of the recent direct detection of gravitational waves by Advanced LIGO, reveals a new…
Recently, we showed that the possibility of an interstellar mission to the closest black hole, while highly speculative and extremely challenging, is not completely unrealistic within the next few decades. Since such a mission might last…
An exact energy expression for a physical black hole is derived by considering the escape of a photon from the black hole. The mass of the black hole within its horizon is found to be twice its mass as observed at infinity. This result is…
The model is constructed, some features of which comes from quantum thin dust shells and is, in fact, an extension of the "no hair" property of classical black hole on a quantum level. It appears that the proposed classical analog of…
Do black holes rotate, and if yes, how fast? This question is fundamental and has broad implications, but still remains open. There are significant observational challenges in current spin determinations, and future facilities offer…
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…
Supermassive black holes are nowadays believed to reside in most local galaxies. Observations have revealed us vast information on the population of local and distant black holes, but the detailed physical properties of these dark massive…
Collider produced black holes are the most exciting prediction from models with large extra dimensions. These black holes exist in an extreme region, in which gravity meets quantum field theory, particle physics, and thermodynamics. An…
The information loss paradox is often presented as an unavoidable consequence of well-established physics. However, in order for a genuine paradox to ensue, not-trivial assumptions about, e.g., quantum effects on spacetime, are necessary.…
As a mysterious celestial body predicted by General Relativity, black holes have been confirmed by observations in recent years. But there are still many unknown properties waiting for us to discover, one of the famous problems is the…
Black holes are capable of reflection: there is a finite probability for any particle that approaches the event horizon to bounce back. The albedo of the black hole depends on its temperature and the energy of the incoming particle. The…
A star surrounded by a black hole generated by it is analyzed. For an outer static observer the black hole mass (and radius) depends on his position in the gravitational field of the star. In spite of the black hole presence, the geometry…
We prove that the anomalous form of Schwarzschild metric within the spatial domain bounded by Schwarzschild pseudosingular surface is a mathematical mishap, devoid of any physical meaning. As a special consequence, the portions of geodesics…
We discuss some of the drawbacks of using event horizons to define black holes and suggest ways in which black holes can be described without event horizons, using trapping horizons. We show that these trapping horizons give rise to…
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…
What does a black hole look like? In 1+3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer's sky often called the black hole shadow, as supported by the EHT observations. In higher…
Perturbations around black holes have been an intriguing topic in the last few decades. They are particularly important today, since they relate to the gravitational wave observations which may provide the unique fingerprint of black holes'…
Stellar-mass black holes ($3$ $M_\odot \lesssim M_{\rm BH} \lesssim 150$ $M_\odot$) are the natural product of the evolution of heavy stars ($M_{\rm star} \gtrsim 20$ $M_\odot$). In our Galaxy, we expect $10^8$-$10^9$ stellar-mass black…
I report on recent progress in the exciting field of Numerical Relativity, with special attention to black hole horizons.
The holographic principle has revealed that physical systems in 3-D space, black holes included, are basically two-dimensional as far as their information content is concerned. This conclusion is complemented by one sketched here: as far as…