scholarly journals BLACK HOLES WITHOUT BOUNDARIES

2008 ◽  
Vol 17 (13n14) ◽  
pp. 2359-2366 ◽  
Author(s):  
ALEX B. NIELSEN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Hawking Radiation ◽  
Information Loss ◽  
Black Hole Thermodynamics ◽  
Event Horizons ◽  
Central Singularity ◽  
Trapping Horizon ◽  
Trapping Horizons

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 thermodynamic behavior and possibly Hawking radiation too. This raises the issue of whether the event horizon or the trapping horizon should be seen as the true boundary of a black hole. This difference is important if we believe that quantum gravity will resolve the central singularity of the black hole and clarifies several of the issues associated with black hole thermodynamics and information loss.

scholarly journals SPHERICALLY SYMMETRIC TRAPPING HORIZONS, THE MISNER–SHARP MASS AND BLACK HOLE EVAPORATION

2009 ◽  
Vol 24 (28n29) ◽  
pp. 5261-5285 ◽  
Author(s):  
ALEX B. NIELSEN ◽  
DONG-HAN YEOM
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Causal Structure ◽  
Information Loss ◽  
Black Hole Thermodynamics ◽  
Spherically Symmetric ◽  
Mixed States ◽  
Unitary Evolution ◽  
Event Horizons ◽  
Trapping Horizons

We discuss some of the issues relating to information loss and black hole thermodynamics in the light of recent work on local black hole horizons. 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 space–time, as is the existence of event horizons. However, black holes need not be defined by event horizons, and in fact we argue that in order to have a fully unitary evolution for black holes, they should be defined in terms of something else, such as a trapping horizon. The Misner–Sharp mass in spherical symmetry shows very simply how trapping horizons can give rise to black hole thermodynamics, Hawking radiation and singularities. We show how the Misner–Sharp mass can also be used to give insights into the process of collapse and evaporation of locally defined black holes.

scholarly journals Physical Properties of Schwarzschild–deSitter Event Horizon Induced by Stochastic Quantum Gravity

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 511
Author(s):  
Claudio Cremaschini ◽  
Massimo Tessarotto
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Event Horizon ◽  
Field Equations ◽  
Central Mass ◽  
Event Horizons ◽  
Covariant Quantum ◽  
Gravitational Fields ◽  
New Type

A new type of quantum correction to the structure of classical black holes is investigated. This concerns the physics of event horizons induced by the occurrence of stochastic quantum gravitational fields. The theoretical framework is provided by the theory of manifestly covariant quantum gravity and the related prediction of an exclusively quantum-produced stochastic cosmological constant. The specific example case of the Schwarzschild–deSitter geometry is looked at, analyzing the consequent stochastic modifications of the Einstein field equations. It is proved that, in such a setting, the black hole event horizon no longer identifies a classical (i.e., deterministic) two-dimensional surface. On the contrary, it acquires a quantum stochastic character, giving rise to a frame-dependent transition region of radial width δr between internal and external subdomains. It is found that: (a) the radial size of the stochastic region depends parametrically on the central mass M of the black hole, scaling as δr∼M3; (b) for supermassive black holes δr is typically orders of magnitude larger than the Planck length lP. Instead, for typical stellar-mass black holes, δr may drop well below lP. The outcome provides new insight into the quantum properties of black holes, with implications for the physics of quantum tunneling phenomena expected to arise across stochastic event horizons.

Black-hole Information Loss Problem: Past, Present, and Future

2020 ◽  
Vol 29 (11) ◽  
pp. 17-25
Author(s):  
Sang-Heon YI ◽  
Dong-han YEOM
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Quantum Information ◽  
Hawking Radiation ◽  
Recent Progress ◽  
Information Loss ◽  
Future Perspectives ◽  
Black Hole Information ◽  
Information Loss Problem

In this article, we discuss the information loss problem of black holes and critically review candidate resolutions of the problem. As a black hole evaporates via Hawking radiation, it seems to lose original quantum information; this indicates that the unitarity of time evolution in quantum mechanics and the fundamental predictability of physics are lost. We categorized candidate resolutions by asking (1) where information is and (2) which principle of physics is changed. We also briefly comment on the recent progress in the string theory community. Finally, we present several remarks for future perspectives.

The remnants in Reissner–Nordström–de Sitter quintessence black hole

2014 ◽  
Vol 29 (26) ◽  
pp. 1450123 ◽  
Author(s):  
Zhongwen Feng ◽  
Li Zhang ◽  
Xiaotao Zu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Quantum Number ◽  
Information Loss ◽  
De Sitter ◽  
Information Loss Paradox

According to the effects of quantum gravity, we investigated the fermion tunneling from the Reissner–Nordström–de Sitter quintessence (RN–dSQ) black hole. The corrected temperature is not only determined by the mass and charge of the black hole, but also depended on the quantum number of the emitted fermion and β, which is a small value representing the effects of quantum gravity. The effects of quantum gravity slowed down the increase of the temperature and led to the remnants of the black hole. We think it is a method to avoid the information loss paradox of black holes.

scholarly journals INFORMATION CONSERVATION IS FUNDAMENTAL: RECOVERING THE LOST INFORMATION IN HAWKING RADIATION

2013 ◽  
Vol 22 (12) ◽  
pp. 1341014 ◽  
Author(s):  
BAOCHENG ZHANG ◽  
QING-YU CAI ◽  
MING-SHENG ZHAN ◽  
LI YOU
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Energy Charge ◽  
Fundamental Principle ◽  
Information Loss ◽  
Information Loss Paradox ◽  
Information Conservation ◽  
World Information ◽  
Conservation Laws Of Energy

In both classical and quantum world, information cannot appear or disappear. This fundamental principle, however, is questioned for a black hole, by the acclaimed "information loss paradox." Based on the conservation laws of energy, charge, and angular momentum, we recently show the total information encoded in the correlations among Hawking radiations equals exactly to the same amount previously considered lost, assuming the nonthermal spectrum of Parikh and Wilczek. Thus the information loss paradox can be falsified through experiments by detecting correlations, for instance, through measuring the covariances of Hawking radiations from black holes, such as the manmade ones speculated to appear in LHC experiments. The affirmation of information conservation in Hawking radiation will shine new light on the unification of gravity with quantum mechanics.

scholarly journals A Second Law for higher curvature gravity

2015 ◽  
Vol 24 (12) ◽  
pp. 1544014 ◽  
Author(s):  
Aron C. Wall
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Entanglement Entropy ◽  
Black Hole Thermodynamics ◽  
Gravity Theory ◽  
Second Law ◽  
Holographic Entanglement Entropy ◽  
Higher Curvature Gravity ◽  
Complete Quantum

The Second Law of black hole thermodynamics is shown to hold for arbitrarily complicated theories of higher curvature gravity, so long as we allow only linearized perturbations to stationary black holes. Some ambiguities in Wald’s Noether charge method are resolved. The increasing quantity turns out to be the same as the holographic entanglement entropy calculated by Dong. It is suggested that only the linearization of the higher curvature Second Law is important, when consistently truncating a UV-complete quantum gravity theory.

On the reality of Hawking radiation

2019 ◽  
Vol 28 (16) ◽  
pp. 2040001
Author(s):  
Asghar Qadir
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Theory ◽  
Hawking Radiation ◽  
Black Hole Thermodynamics ◽  
The Public ◽  
Roger Penrose ◽  
The Subject

Hawking radiation caught the imagination of the public and physicists alike, because it seemed so counter-intuitive. By their very definition, black holes were supposed to endlessly absorb, but never emit, matter and energy. Yet, Hawking argued that taking Quantum Theory into account, they would radiate. The further belief was that Bekenstein and Hawking had developed the field of Black Hole Thermodynamics. Here I want to correct this impression and give due credit to Roger Penrose for founding the subject. Further, I discuss the question of whether Hawking radiation should be expected to really exist, arguing that there is reason to doubt it.

scholarly journals Minimal length and the flow of entropy from black holes

2018 ◽  
Vol 27 (14) ◽  
pp. 1847028 ◽  
Author(s):  
Ana Alonso-Serrano ◽  
Mariusz P. Da̧browski ◽  
Hussain Gohar
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Uncertainty Principle ◽  
Hawking Radiation ◽  
Generalized Uncertainty Principle ◽  
Minimal Length ◽  
Evaporation Process ◽  
Black Hole Evaporation ◽  
The Impact

The existence of a minimal length, predicted by different theories of quantum gravity, can be phenomenologically described in terms of a generalized uncertainty principle. We consider the impact of this quantum gravity motivated effect onto the information budget of a black hole and the sparsity of Hawking radiation during the black hole evaporation process. We show that the information is not transmitted at the same rate during the final stages of the evaporation, and that the Hawking radiation is not sparse anymore when the black hole approaches the Planck mass.

scholarly journals PRECURSORS SEE INSIDE BLACK HOLES

2003 ◽  
Vol 12 (09) ◽  
pp. 1693-1698 ◽  
Author(s):  
VERONIKA E. HUBENY
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Black Hole Horizon ◽  
Information Paradox ◽  
Event Horizons ◽  
Global Nature ◽  
Singularity Resolution ◽  
Nonlocal Nature

We consider, within a string theoretic context, the accessibility of events inside a black hole horizon. We present a gedankenexperiment which uses the nonlocal nature of precursors in the AdS/CFT correspondence, as well as the global nature of event horizons, to argue that the dual field theory does contain information about physics inside black holes. This alleviates the causal obstacles to accessing behind-the-horizon physics, thereby rendering more tractable certain long-standing questions of quantum gravity, such as the information paradox and possibly even singularity resolution.

scholarly journals Black hole thermodynamics

2014 ◽  
Vol 23 (11) ◽  
pp. 1430023 ◽  
Author(s):  
S. Carlip
Keyword(s):  
Mechanical Properties ◽  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Information Loss ◽  
Black Hole Thermodynamics ◽  
Information Loss Paradox ◽  
Black Bodies ◽  
Statistical Mechanical ◽  
The Many

The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this paper, will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

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