scholarly journals THE CARDY–VERLINDE EQUATION IN A SPHERICAL SYMMETRIC GRAVITATIONAL COLLAPSE

2010 ◽  
Vol 25 (30) ◽  
pp. 5529-5542
Author(s):  
G. MAIELLA ◽  
C. STORNAIOLO
Keyword(s):  
Black Hole ◽  
Gravitational Collapse ◽  
Black Hole Entropy ◽  
Holographic Principle ◽  
Verlinde Formula

The Cardy–Verlinde formula is analyzed in the contest of the gravitational collapse. Starting from the holographic principle, we show how the equations for a homogeneous and isotropic gravitational collapse describe the formation of the black hole entropy. Some comments on the role of the entangled entropy and the connection with the c-theorem are made.

scholarly journals Hairy black hole entropy and the role of solitons in three dimensions

2012 ◽  
Vol 2012 (2) ◽  
Author(s):  
Francisco Correa ◽  
Cristián Martínez ◽  
Ricardo Troncoso
Keyword(s):  
Black Hole ◽  
Black Hole Entropy ◽  
Three Dimensions ◽  
Hairy Black Hole

scholarly journals Logarithmic Corrections to the FRW Brane Cosmology from 5d Schwarzschild–de Sitter Black Hole

2003 ◽  
Vol 18 (19) ◽  
pp. 3395-3416 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov ◽  
Sachiko Ogushi
Keyword(s):  
Black Hole ◽  
Black Hole Entropy ◽  
Slight Modification ◽  
Thermal Fluctuations ◽  
De Sitter ◽  
Brane Cosmology ◽  
Verlinde Formula ◽  
Logarithmic Corrections ◽  
Constant Change ◽  
Sds Black Hole

Thermodynamics of 5d SdS black hole is considered. Thermal fluctuations define the (sub-dominant) logarithmic corrections to black hole entropy and then to Cardy–Verlinde formula and to FRW brane cosmology. We demonstrate that logarithmic terms (which play the role of effective cosmological constant) change the behavior of 4d spherical brane in dS, SdS or Nariai bulk. In particularly, bounce Universe occurs or 4d dS brane expands to its maximum and then shrinks. The entropy bounds are also modified by next-to-leading terms. Out of braneworld context the logarithmic terms may suggest slight modification of standard FRW cosmology.

scholarly journals Comment on “Black Hole Entropy: A Closer Look”

Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1110
Author(s):  
Pedro Pessoa ◽  
Bruno Arderucio Costa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Additive Functional ◽  
Important Distinction

In a recent paper (Entropy 2020, 22(1), 17), Tsallis states that entropy—as in Shannon or Kullback–Leiber’s definitions—is inadequate to interpret black hole entropy and suggests that a new non-additive functional should take the role of entropy. Here we counterargue by explaining the important distinction between the properties of extensivity and additivity; the latter is fundamental for entropy, while the former is a property of particular thermodynamical systems that is not expected for black holes. We also point out other debatable statements in his analysis of black hole entropy.

scholarly journals TOWARDS A THEORY OF QUANTUM BLACK HOLES

2002 ◽  
Vol 17 (06n07) ◽  
pp. 979-988 ◽  
Author(s):  
VICTOR BEREZIN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Gravitational Collapse ◽  
Black Hole Entropy ◽  
Black Hole Mass ◽  
Quantum Black Hole ◽  
Classical Analog ◽  
Hole Model ◽  
Specific Quantum

We describe some specific quantum black hole model. It is pointed out that the origin of a black hole entropy is the very process of quantum gravitational collapse. The quantum black hole mass spectrum is extracted from the mass spectrum of the gravitating source. The classical analog of quantum black hole is constructed.

scholarly journals Quantum BTZ black hole

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Roberto Emparan ◽  
Antonia Micol Frassino ◽  
Benson Way
Keyword(s):  
Black Hole ◽  
Stress Tensor ◽  
Three Dimensional ◽  
Black Hole Entropy ◽  
Btz Black Hole ◽  
Dimensional Solution ◽  
Quantum Black Hole ◽  
Strongly Coupled ◽  
Conformal Fields

Abstract We study a holographic construction of quantum rotating BTZ black holes that incorporates the exact backreaction from strongly coupled quantum conformal fields. It is based on an exact four-dimensional solution for a black hole localized on a brane in AdS4, first discussed some years ago but never fully investigated in this manner. Besides quantum CFT effects and their backreaction, we also investigate the role of higher-curvature corrections in the effective three-dimensional theory. We obtain the quantum-corrected geometry and the renormalized stress tensor. We show that the quantum black hole entropy, which includes the entanglement of the fields outside the horizon, satisfies the first law of thermodynamics exactly, even in the presence of backreaction and with higher-curvature corrections, while the Bekenstein-Hawking-Wald entropy does not. This result, which involves a rather non-trivial bulk calculation, shows the consistency of the holographic interpretation of braneworlds. We compare our renormalized stress tensor to results derived for free conformal fields, and for a previous holographic construction without backreaction effects, which is shown to be a limit of the solutions in this article.

scholarly journals THE QUANTUM GRAVITATIONAL BLACK HOLE IS NEITHER BLACK NOR WHITE

2004 ◽  
Vol 13 (10) ◽  
pp. 2369-2373 ◽  
Author(s):  
T. P. SINGH ◽  
CENALO VAZ
Keyword(s):  
Black Hole ◽  
Gravitational Collapse ◽  
Black Hole Entropy ◽  
Accurate Estimate ◽  
Information Loss ◽  
Mass Energy ◽  
Central Black Hole ◽  
Information Loss Paradox ◽  
Lattice Regularization ◽  
Microscopic Origin

Understanding the end state of black hole evaporation, the microscopic origin of black hole entropy, the information loss paradox, and the nature of the singularity arising in gravitational collapse — these are outstanding challenges for any candidate quantum theory of gravity. Recently, a midisuperspace model of quantum gravitational collapse has been solved using a lattice regularization scheme. It is shown that the mass of an eternal black hole follows the Bekenstein spectrum, and a related argument provides a fairly accurate estimate of the entropy. The solution also describes a quantized mass–energy distribution around a central black hole, which in the WKB approximation, is precisely Hawking radiation. The leading quantum gravitational correction makes the spectrum non-thermal, thus providing a plausible resolution of the information loss problem.

scholarly journals GRAVITATIONAL COLLAPSE WITH TANGENTIAL PRESSURE

2011 ◽  
Vol 20 (04) ◽  
pp. 463-495 ◽  
Author(s):  
DANIELE MALAFARINA ◽  
PANKAJ S. JOSHI
Keyword(s):  
Black Hole ◽  
Gravitational Collapse ◽  
Dust Cloud ◽  
Naked Singularity ◽  
Final States ◽  
Singularity Formation ◽  
Tangential Pressure ◽  
Final State ◽  
Collapse Models

Using the general formalism for spherical gravitational collapse developed in [P. S. Joshi and I. H. Dwivedi, Class. Quant. Grav.16 (1999) 41; P. S. Joshi and R. Goswami, Phys. Rev. D76 (2007) 084026], we investigate here the final fate of a spherical distribution of a matter cloud, where radial pressures vanish but tangential pressures are nonzero. Within this framework, firstly we examine the effect of introducing a generic small pressure in a well-known black hole formation process, which is that of an otherwise pressure-free dust cloud. The intriguing result we find is that a dust collapse that was going to a black hole final state could now go to a naked singularity final configuration, when arbitrarily small tangential pressures are introduced. The implications of such a scenario are discussed in some detail. Secondly, the approach here allows us to generalize the earlier results obtained on gravitational collapse with nonzero tangential pressure, in the presence of a nonzero cosmological constant. Finally, we discuss the genericity of black hole and naked singularity formation in collapse with nonzero tangential pressure. The treatment here gives a unified and complete picture on collapse final states, in terms of black hole and naked singularity formation, generalizing the earlier results obtained for this class of collapse models. Thus the role of tangential stresses towards determining collapse end-states emerges in a straightforward and transparent manner in our treatment.

Statistical Mechanical Interpretation of Black Hole Entropy

1994 ◽  
Vol 49 (11) ◽  
pp. 1023-1030
Author(s):  
F. Winterberg
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Gravitational Collapse ◽  
Black Hole Entropy ◽  
Field Energy ◽  
Planck Mass ◽  
Statistical Mechanical ◽  
Mechanical Interpretation ◽  
The Universe ◽  
Matter Energy

Abstract It is shown that the Bekenstein-Hawking formula for the entropy of a black hole can be given a statistical mechanical interpretation in terms of Planck mass particles. It is furthermore shown that the previously proposed Planck aether model (assuming that space is densely filled with an equal number of positive and negative Planck masses) gives an expression for the black hole entropy, different from the Bekenstein-Hawking formula, with the entropy proportional to the 3/4 power of the black hole surface rather than proportional to its surface. The Planck aether model also gives an expression for the entropy of the gravitational field, which for a black hole is the entropy of negative Planck masses. To be consistent with Nernst's theorem, it is conjectured that this gravitational field entropy is negative. For a universe in which the sum of the positive matter energy and the negative gravitational field energy is zero, the sum of the matter and gravitational field entropy would therefore vanish as well. Because the positive and negative Planck masses are separated from each other, a cancellation of their entropy appears to be only possible in the event of a gravitational collapse of the universe as a whole.

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