ENTROPY OF SCHWARZSCHILD–de SITTER BLACK HOLE IN NON-THERMAL-EQUILIBRIUM

2001 ◽  
Vol 16 (11) ◽  
pp. 719-723 ◽  
Author(s):  
REN ZHAO ◽  
JUNFANG ZHANG ◽  
LICHUN ZHANG
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Thermal Equilibrium ◽  
Gordon Equation ◽  
Brick Wall ◽  
De Sitter ◽  
Logarithmic Term ◽  
Klein Gordon ◽  
Klein Gordon Equation ◽  
Wall Method

Starting from the Klein–Gordon equation, we calculate the entropy of Schwarzschild–de Sitter black hole in non-thermal-equilibrium by using the improved brick-wall method-membrane model. When taking the proper cutoff in the obtained result, we obtain that both black hole's entropy and cosmic entropy are proportional to the areas of event horizon. We avoid the logarithmic term and stripped term in the original brick-wall method. It offers a new way of studying the entropy of the black hole in non-thermal-equilibrium.

THE ENTROPY CALCULATED VIA BRICK-WALL METHOD COMES FROM A THIN FILM NEAR THE EVENT HORIZON

2001 ◽  
Vol 16 (23) ◽  
pp. 3793-3803 ◽  
Author(s):  
WENBIAO LIU ◽  
ZHENG ZHAO
Keyword(s):  
Thin Film ◽  
Black Hole ◽  
Event Horizon ◽  
Fundamental Problem ◽  
Dirac Field ◽  
Brick Wall ◽  
De Sitter ◽  
Wall Model ◽  
Mass Approximation ◽  
Wall Method

The brick-wall method put forward by 't Hooft has contributed a great deal to the understanding and calculating of the entropy of a black hole. However, there are some drawbacks in it such as little mass approximation, neglecting logarithm terms, and taking the term including L3 as a contribution of the vacuum surrounding the black hole. Moreover, the fundamental problem is why the entropy of scalar field or Dirac field surrounding a black hole is the entropy of the black hole itself. It is well known that the event horizon is the characteristic of a black hole. The entropy calculation of a black hole should be only related to its horizon. Due to this analysis, we improve the brick-wall model by taking that the entropy of a black hole is only contributed by a thin film near the event horizon. This improvement not only gives us a satisfied result, but also avoids the drawbacks in the original brick-wall method. It is found that there is an intrinsic relation between the event horizon and the entropy. We also calculate the entropy of Schwarzschild–de Sitter space–time via the improved method, which can hardly be resolved via the original model.

scholarly journals Existence of exponentially growing finite energy solutions for the charged Klein–Gordon equation on the de Sitter–Kerr–Newman metric

2021 ◽  
Vol 18 (02) ◽  
pp. 293-310
Author(s):  
Nicolas Besset ◽  
Dietrich Häfner
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Half Plane ◽  
Gordon Equation ◽  
Finite Energy ◽  
De Sitter ◽  
Klein Gordon ◽  
Upper Half Plane ◽  
Small Charge ◽  
Klein Gordon Equation

We show the existence of exponentially growing finite energy solutions for the charged Klein–Gordon equation on the De Sitter–Kerr–Newman metric for small charge and mass of the field and small angular momentum of the black hole. The mechanism behind is that the zero resonance that exists for zero charge, mass and angular momentum moves into the upper half plane.

scholarly journals The Goursat problem at the horizons for the Klein–Gordon equation on the de Sitter–Kerr metric

2021 ◽  
Vol 18 (03) ◽  
pp. 609-652
Author(s):  
Pascal Millet
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Gordon Equation ◽  
Goursat Problem ◽  
Main Topic ◽  
Kerr Metric ◽  
De Sitter ◽  
Massless Field ◽  
Klein Gordon ◽  
Klein Gordon Equation

The main topic of this paper is the Goursat problem at the horizon for the Klein–Gordon equation on the De Sitter–Kerr metric when the angular momentum (per unit of mass) of the black hole is small. Indeed, we solve the Goursat problem for fixed angular momentum [Formula: see text] of the field (with the restriction that [Formula: see text] is not zero in the case of a massless field).

scholarly journals FINITE ACTION KLEIN–GORDON SOLUTIONS ON LORENTZIAN MANIFOLDS

2006 ◽  
Vol 03 (07) ◽  
pp. 1349-1357 ◽  
Author(s):  
V. V. KOZLOV ◽  
I. V. VOLOVICH
Keyword(s):  
Mass Spectrum ◽  
Elliptic Equations ◽  
Gordon Equation ◽  
Infinite Family ◽  
De Sitter ◽  
Lorentzian Manifolds ◽  
Klein Gordon ◽  
Finite Action ◽  
Discrete Mass ◽  
Klein Gordon Equation

The eigenvalue problem for the square integrable solutions is studied usually for elliptic equations. In this paper we consider such a problem for the hyperbolic Klein–Gordon equation on Lorentzian manifolds. The investigation could help to answer the question why elementary particles have a discrete mass spectrum. An infinite family of square integrable solutions for the Klein–Gordon equation on the Friedman type manifolds is constructed. These solutions have a discrete mass spectrum and a finite action. In particular the solutions on de Sitter space are investigated.

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