scholarly journals Black hole entropy and boundary conditions

2020 ◽  
Vol 101 (12) ◽  
Author(s):  
H. Khodabakhshi ◽  
A. Shirzad ◽  
F. Shojai ◽  
Robert B. Mann
Keyword(s):  
Black Hole ◽  
Boundary Conditions ◽  
Black Hole Entropy

scholarly journals Membrane paradigm from near-horizon soft hair

2018 ◽  
Vol 27 (14) ◽  
pp. 1847006 ◽  
Author(s):  
D. Grumiller ◽  
M. M. Sheikh-Jabbari
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Boundary Conditions ◽  
Degrees Of Freedom ◽  
Black Hole Entropy ◽  
Heisenberg Algebra ◽  
Zero Energy ◽  
Shear Deformations ◽  
Dynamical Degrees ◽  
Area Preserving

The membrane paradigm posits that black hole microstates are dynamical degrees of freedom associated with a physical membrane vanishingly close to the black hole’s event horizon. The soft hair paradigm postulates that black holes can be equipped with zero-energy charges associated with residual diffeomorphisms that label near-horizon degrees of freedom. In this paper we argue that the latter paradigm implies the former. More specifically, we exploit suitable near-horizon boundary conditions that lead to an algebra of “soft hair charges” containing infinite copies of the Heisenberg algebra, associated with area-preserving shear deformations of black hole horizons. We employ the near-horizon soft hair and its Heisenberg algebra to provide a formulation of the membrane paradigm and show how it accounts for black hole entropy.

R-N black holes can be transformed into K-N black holes

2021 ◽  
Author(s):  
Wen-Xiang Chen
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Boundary Conditions ◽  
Black Hole Entropy ◽  
Charged Black Hole ◽  
Naked Singularities ◽  
Hole Charge

If there is no strong cosmic supervision conjecture, there may be naked singularities. The decrease in black hole entropy indicates that there is periodicity inside the black hole.This article points out that when the entropy of a black hole decreases, its enthalpy will increase, and the black hole charge will be converted into angular momentum through a certain channel. This article hereby asserts that a non-rotating charged black hole will transform into a rotating charged black hole under the effect of superradiation under preset boundary conditions.

scholarly journals New non-extremal and BPS hairy black holes in gauged $$ \mathcal{N} $$ = 2 and $$ \mathcal{N} $$ = 8 supergravity

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Andres Anabalon ◽  
Dumitru Astefanesei ◽  
Antonio Gallerati ◽  
Mario Trigiante
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Boundary Conditions ◽  
Charged Black Hole ◽  
Dual Theory ◽  
Real Numbers ◽  
Hairy Black Holes ◽  
Interpolation Parameter ◽  
Black Hole Solutions ◽  
Extremal Black Holes

Abstract In this article we study a family of four-dimensional, $$ \mathcal{N} $$ N = 2 supergravity theories that interpolates between all the single dilaton truncations of the SO(8) gauged $$ \mathcal{N} $$ N = 8 supergravity. In this infinitely many theories characterized by two real numbers — the interpolation parameter and the dyonic “angle” of the gauging — we construct non-extremal electrically or magnetically charged black hole solutions and their supersymmetric limits. All the supersymmetric black holes have non-singular horizons with spherical, hyperbolic or planar topology. Some of these supersymmetric and non-extremal black holes are new examples in the $$ \mathcal{N} $$ N = 8 theory that do not belong to the STU model. We compute the asymptotic charges, thermodynamics and boundary conditions of these black holes and show that all of them, except one, introduce a triple trace deformation in the dual theory.

scholarly journals Reply to Pessoa, P.; Arderucio Costa, B., Comment on “Tsallis, C. Black Hole Entropy: A Closer Look. Entropy 2020, 22, 17”

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 630
Author(s):  
Constantino Tsallis
Keyword(s):  
Black Hole ◽  
Black Hole Entropy ◽  
Recent Comment

In the present Reply we restrict our focus only onto the main erroneous claims by Pessoa and Costa in their recent Comment (Entropy 2020, 22, 1110).

scholarly journals Area Entropy and Quantized Mass of Black Holes from Information Theory

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 858
Author(s):  
Dongshan He ◽  
Qingyu Cai
Keyword(s):  
Information Theory ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Quantum Corrections ◽  
Compton Wavelength ◽  
Information Theoretic ◽  
Curved Space ◽  
Thermodynamic Entropy ◽  
Hole Area ◽  
The Relationship

In this paper, we present a derivation of the black hole area entropy with the relationship between entropy and information. The curved space of a black hole allows objects to be imaged in the same way as camera lenses. The maximal information that a black hole can gain is limited by both the Compton wavelength of the object and the diameter of the black hole. When an object falls into a black hole, its information disappears due to the no-hair theorem, and the entropy of the black hole increases correspondingly. The area entropy of a black hole can thus be obtained, which indicates that the Bekenstein–Hawking entropy is information entropy rather than thermodynamic entropy. The quantum corrections of black hole entropy are also obtained according to the limit of Compton wavelength of the captured particles, which makes the mass of a black hole naturally quantized. Our work provides an information-theoretic perspective for understanding the nature of black hole entropy.

THE BLACK HOLE ENTROPY BOUND AND THE MAXIMUM TEMPERATURE FOR MESON FORMATION IN THE NUCLEAR FIREBALL

1991 ◽  
Vol 06 (33) ◽  
pp. 3039-3045 ◽  
Author(s):  
JISHNU DEY ◽  
MIRA DEY ◽  
MARCELO SCHIFFER ◽  
LAURO TOMIO
Keyword(s):  
Black Hole ◽  
Simple Model ◽  
Black Hole Entropy ◽  
Heavy Ion ◽  
Black Hole Thermodynamics ◽  
Maximum Temperature ◽  
Ion Collisions ◽  
Pion Interferometry ◽  
Entropy Bound ◽  
Confined System

The entropy bound from black hole thermodynamics can be invoked to set limits for temperatures at which hadrons can survive as a confined system. We find that this implies that the pion can be formed in heavy ion collisions, much later than heavier mesons, for example the ρ-meson, when the fireball is cooler. The temperature found in a simple model agree qualitatively with experiment. We also suggest that this may be the reason why in pion interferometry experiments the space-time volume of the pion source seems large.

scholarly journals Near extremal black hole entropy as entanglement entropy viaAdS2/CFT1

2008 ◽  
Vol 77 (6) ◽  
Author(s):  
Tatsuo Azeyanagi ◽  
Tatsuma Nishioka ◽  
Tadashi Takayanagi
Keyword(s):  
Black Hole ◽  
Entanglement Entropy ◽  
Black Hole Entropy ◽  
Extremal Black Hole
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