scholarly journals HOLOGRAPHIC ENTROPY ON THE BRANE IN de SITTER SCHWARZSCHILD SPACE

2002 ◽  
Vol 17 (01) ◽  
pp. 51-58 ◽  
Author(s):  
SACHIKO OGUSHI
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Black Hole Entropy ◽  
Brane Tension ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Verlinde Formula ◽  
The Relationship ◽  
Friedmann Robertson Walker ◽  
Schwarzschild Background

The relationship between the entropy of de Sitter (dS) Schwarzschild space and that of the CFT, which lives on the brane, is discussed by using Friedmann–Robertson–Walker (FRW) equations and Cardy–Verlinde formula. The cosmological constant appears on the brane with time-like metric in dS Schwarzschild background. On the other hand, in case of the brane with space-like metric in dS Schwarzschild background, the cosmological constant of the brane does not appear because we can choose brane tension to cancel it. We show that when the brane crosses the horizon of dS Schwarzschild black hole, both for time-like and space-like cases, the entropy of the CFT exactly agrees with the black hole entropy of five-dimensional dS background as it happens in the AdS/CFT correspondence.

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.

GRAVITATIONAL THERMODYNAMICS AND THE WHEELER–DEWITT EQUATION

2011 ◽  
Vol 20 (01) ◽  
pp. 23-42 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Black Hole ◽  
Wave Function ◽  
Boundary Conditions ◽  
Cosmological Constant ◽  
Apparent Horizon ◽  
De Sitter Space ◽  
Hawking Temperature ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Gravitational Thermodynamics

In a previous paper, we have derived the Hawking temperature T H = 1/8πM for a Schwarzschild black hole of mass M, starting from the Wheeler–DeWitt for the wave function Ψ on the apparent horizon, due to Tomimatsu. Here we discuss the derivation of this result in greater detail, with particular regard to the Euclideanization procedure involved and the boundary conditions on the horizon. Further, analysis of the de Sitter space-time generated by a cosmological constant Λ yields the temperature [Formula: see text] found by Gibbons and Hawking, which thus vindicates the method. The emission of radiation occurs with preservation of unitarity, and hence entropy, which is substantiated by a global thermodynamical argument in the case of the black hole.

scholarly journals SPACE TIME FOAM

2002 ◽  
Vol 17 (06n07) ◽  
pp. 829-832 ◽  
Author(s):  
REMO GARATTINI
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Ground State ◽  
Casimir Energy ◽  
Space Time ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Positive Cosmological Constant ◽  
Hole Transition

In the context of a model of space-time foam, made by N wormholes we discuss the possibility of having a foam formed by different configurations. An equivalence between Schwarzschild and Schwarzschild-Anti-de Sitter wormholes in terms of Casimir energy is shown. An argument to discriminate which configuration could represent a foamy vacuum coming from Schwarzschild black hole transition frequencies is used. The case of a positive cosmological constant is also discussed. Finally, a discussion involving charged wormholes leads to the conclusion that they cannot be used to represent a ground state of the foamy type.

scholarly journals QUANTUM BOUNDS FOR GRAVITATIONAL DE SITTER ENTROPY AND THE CARDY–VERLINDE FORMULA

2001 ◽  
Vol 16 (18) ◽  
pp. 1181-1192 ◽  
Author(s):  
S. NOJIRI ◽  
O. OBREGON ◽  
S. D. ODINTSOV ◽  
H. QUEVEDO ◽  
M. P. RYAN
Keyword(s):  
Cosmological Constant ◽  
De Sitter Space ◽  
Quantum Corrections ◽  
Hamiltonian Constraint ◽  
De Sitter ◽  
Entropy Formula ◽  
Verlinde Formula ◽  
Effective Cosmological Constant ◽  
Different Types ◽  
Friedmann Robertson Walker

We analyze different types of quantum corrections to the Cardy–Verlinde entropy formula in a Friedmann–Robertson–Walker universe and in an (anti)-de Sitter space. In all cases we show that quantum corrections can be represented by an effective cosmological constant which is then used to redefine the parameters entering the Cardy–Verlinde formula so that it becomes valid also with quantum corrections, a fact that we interpret as a further indication of its universality. A proposed relation between Cardy–Verlinde formula and the ADM Hamiltonian constraint is given.

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.

scholarly journals PRIMORDIAL BLACK HOLE FORMATION FROM INFLATON

2000 ◽  
Vol 09 (06) ◽  
pp. 705-710 ◽  
Author(s):  
XIN HE MENG ◽  
BIN WANG ◽  
S. FENG
Keyword(s):  
Black Hole ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
De Sitter ◽  
Hole Formation ◽  
Black Hole Formation ◽  
Expansion Of The Universe ◽  
Slow Rolling ◽  
The Relationship ◽  
The Universe

Measurements of the distances to SNe Ia have produced strong evidence that the expansion of the Universe is really accelarating, implying the existence of a nearly uniform component of dark energy with the simplest explanation as a cosmological constant. In this paper a small changing cosmological term is proposed, which is a function of a slow-rolling scalar field, by which the de Sitter primordial black holes' properties, for both charged and uncharged cases, are carefully examined and the relationship between the black hole formation and the energy transfer of the inflaton is eluciated. The criterion for primordial black hole formation is given.

scholarly journals The (A)symmetry between the Exterior and Interior of a Schwarzschild Black Hole

2018 ◽  
Author(s):  
Pawel Gusin ◽  
Andy Augousti ◽  
Filip Formalik ◽  
Andrzej Radosz
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Equations Of Motion ◽  
Coordinate Systems ◽  
Schwarzschild Black Hole ◽  
Schwarzschild Spacetime ◽  
The Relationship

A black hole in a Schwarzschild spacetime is considered. A transformation is proposed that describes the relationship between the coordinate systems exterior and interior to an event horizon. Application of this transformation permits considerations of the (a)symmetry of a range of phenomena taking place on both sides of the event horizon. The paper investigates two distinct problems of a uniformly accelerated particle. In one of these, although the equations of motion are the same in the regions on both sides, the solutions turn out to be very different. This manifests the differences of the properties of these two ranges.

scholarly journals Quantum gravity: Physics from supergeometries

2014 ◽  
Vol 11 (08) ◽  
pp. 1450067 ◽  
Author(s):  
Diego Julio Cirilo-Lombardo ◽  
Thiago Prudêncio
Keyword(s):  
Black Hole ◽  
Coherent State ◽  
Line Element ◽  
Black Hole Entropy ◽  
Quantum Structure ◽  
Geometrical Object ◽  
Large N ◽  
General Basis ◽  
The Relationship ◽  
Classical Radiation

We show that the metric (line element) is the first geometrical object to be associated to a discrete (quantum) structure of the spacetime without necessity of black hole-entropy-area arguments, in sharp contrast with other attempts in the literature. To this end, an emergent metric solution obtained previously in [ Phys. Lett. B661 (2008) 186–191] from a particular non-degenerate Riemannian superspace is introduced. This emergent metric is described by a physical coherent state belonging to the metaplectic group Mp (n) with a Poissonian distribution at lower n (number basis) restoring the classical thermal continuum behavior at large n(n → ∞), or leading to non-classical radiation states, as is conjectured in a quite general basis by means of the Bekenstein–Mukhanov effect. Group-dependent conditions that control the behavior of the macroscopic regime spectrum (thermal or not), as the relationship with the problem of area/entropy of the black hole are presented and discussed.

scholarly journals Extremal Cosmological Black Holes in Horndeski Gravity and the Anti-Evaporation Regime

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 210
Author(s):  
Ismael Ayuso ◽  
Diego Sáez-Chillón Gómez
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmological Constant ◽  
Linear Order ◽  
Scalar Tensor Theory ◽  
De Sitter ◽  
Tensor Theory ◽  
Effective Cosmological Constant ◽  
Cosmological Black Holes ◽  
Extremal Black Holes

Extremal cosmological black holes are analysed in the framework of the most general second order scalar-tensor theory, the so-called Horndeski gravity. Such extremal black holes are a particular case of Schwarzschild-De Sitter black holes that arises when the black hole horizon and the cosmological one coincide. Such metric is induced by a particular value of the effective cosmological constant and is known as Nariai spacetime. The existence of this type of solutions is studied when considering the Horndeski Lagrangian and its stability is analysed, where the so-called anti-evaporation regime is studied. Contrary to other frameworks, the radius of the horizon remains stable for some cases of the Horndeski Lagrangian when considering perturbations at linear order.

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