THE FERMIONIC ENTROPY OF SPHERICALLY SYMMETRIC BLACK HOLES

2000 ◽  
Vol 15 (31) ◽  
pp. 1901-1914 ◽  
Author(s):  
YOU-GEN SHEN

The free energy and entropy for Dirac field is derived in the general spherically symmetric black hole background, by using 't Hooft's brick wall model. It is found that, in such a black hole background, fermionic entropy is 7/2 times the value of bosonic entropy.

2001 ◽  
Vol 10 (04) ◽  
pp. 539-546 ◽  
Author(s):  
YOU-GEN SHEN ◽  
DA-MING CHEN

The fermionic free energy and entropy are calculated in Garfinkle–Horowitz–Strominger dilatonic black hole background spacetime, by using 't Hfoot's brick wall model. It turns out that the fermionic entropy in Garfinkle–Horowitz–Strominger dilatonic black hole back ground spacetime is 7/2 times the Bosonic entropy.


2013 ◽  
Vol 28 (07) ◽  
pp. 1350009
Author(s):  
LICHUN ZHANG ◽  
HUAIFAN LI ◽  
REN ZHAO ◽  
RONGGEN CAI

In a dielectric black hole background, photons will be radiated via Hawking evaporation mechanism. In this paper, we calculate the entanglement entropy associated with a static dielectric black hole by employing 't Hooft's brick-wall model. It is found that the lowest energy of radiated particles is coordinate dependent. The resulted entanglement entropy is composed of three parts: a parameter independent leading constant term [Formula: see text], a logarithmic correction term and some series terms. The convergency of the series terms is also discussed.


2003 ◽  
Vol 12 (06) ◽  
pp. 1083-1094 ◽  
Author(s):  
XUEJUN YANG ◽  
YIWEN HAN ◽  
ZHENG ZHAO

The entropy of a rotating and arbitrarily accelerating black hole whose metric changes slowly is calculated using the thin film brick-wall model. We obtain the entropy density at every point of the horizon surface and the total entropy of the black hole. The results show that the entropy of the nonstationary black hole is also proportional to the surface area of the black hole's event horizon as in the cases of stationary black holes.


1999 ◽  
Vol 14 (04) ◽  
pp. 239-246 ◽  
Author(s):  
YOU-GEN SHEN ◽  
DA-MING CHEN

By using 't Hooft's brick wall model, the corrections for a massless quantum scalar field to the black hole entropy are studied in rotating U (1) ⊗ U (1)-dilaton black hole space–time. The free energy and entropy for this case are calculated, and in Hartle–Hawking states, the derived quantum entropy is composed of the geometric part and the non-geometric part which is logrithmically divergent. It turns out that the logrithmic part is related to the characteristic quantities of a black hole.


2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Piyabut Burikham ◽  
Supakchai Ponglertsakul ◽  
Taum Wuthicharn

AbstractA number of near-extremal conditions are utilized to simplify the equation of motion of the neutral scalar perturbations in generalized spherically symmetric black hole background into a differential equation with the Pöschl–Teller potential. An analytic formula for quasinormal frequencies is obtained. The analytic formula is then used to investigate strong cosmic censorship conjectures (SCC) of the generalized black hole spacetime for the smooth initial data. The Christodoulou version of the SCC is found to be violated for certain regions of the black hole parameter space including the black holes in general relativity while the $$C^{1}$$ C 1 version of the SCC is always valid.


2001 ◽  
Vol 16 (08) ◽  
pp. 489-495
Author(s):  
WEIGANG QIU ◽  
JIANJUN XU ◽  
RU-KENG SU ◽  
BIN WANG

Using brick wall model, the first quantum corrections to the extreme Reissner–Nordström black hole entropy due to scalar field as well as electromagnetic field have been calculated. Different quantum entropy values have been obtained for two different kinds of extreme black holes.


2001 ◽  
Vol 16 (23) ◽  
pp. 3793-3803 ◽  
Author(s):  
WENBIAO LIU ◽  
ZHENG ZHAO

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.


2000 ◽  
Vol 15 (28) ◽  
pp. 1739-1747 ◽  
Author(s):  
LI XIANG ◽  
ZHAO ZHENG

We point out that the brick-wall model cannot be applied to the nonstatic black hole. In the case of a static hole, we propose a new model where the black hole entropy is attributed to the dynamical degrees of the field covering the two-dimensional membrane just outside the horizon. A cutoff different from the model of 't Hooft is necessarily introduced. It can be treated as an increase in horizon because of the space–time fluctuations. We also apply our model to the nonequilibrium and nonstatic cases, such as Schwarzschild–de Sitter and Vaidya space–times. In the nonstatic case, the entropy relies on a time-dependent cutoff.


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