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

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.

2019 ◽  
Vol 34 (27) ◽  
pp. 1950222
Author(s):  
Abdul Jawad ◽  
Shahid Chaudhary

The impact of thermal fluctuations on the thermodynamics of Born–Infeld–anti-de Sitter black hole is being investigated. For this purpose, we analyze the consequences of logarithmic corrections on thermodynamics potentials like Helmholtz and Gibbs. We find out the relations for critical points and stability and observe that thermal corrections play a vital role in them.


2002 ◽  
Vol 17 (01) ◽  
pp. 51-58 ◽  
Author(s):  
SACHIKO OGUSHI

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.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Akram Sadat Sefiedgar

The emergence of the quantum gravitational effects in a very high energy regime necessitates some corrections to the thermodynamics of black holes. In this letter, we investigate a possible modification to the thermodynamics of Schwarzschild anti-de Sitter (SAdS) black holes due to rainbow gravity model. Using the correspondence between a (d+1)-dimensional SAdS black hole and a conformal filed theory ind-dimensional spacetime, one may find the corrections to the Cardy-Verlinde formula from the modified thermodynamics of the black hole. Furthermore, we show that the corrected Cardy-Verlinde formula can also be derived by redefining the Virasoro operator and the central charge.


2002 ◽  
Vol 17 (32) ◽  
pp. 2089-2094 ◽  
Author(s):  
M. R. SETARE

In this paper we discuss the question of whether the entropy of cosmological horizon in topological Reissner–Nordström–de Sitter spaces can be described by the Cardy–Verlinde formula, which is supposed to be an entropy formula of conformal field theory in any dimension. Furthermore, we find that the entropy of black hole horizon can also be rewritten in terms of the Cardy–Verlinde formula for these black holes in de Sitter spaces, if we use the definition due to Abbott and Deser for conserved charges in asymptotically de Sitter spaces. Our result is in favour of the dS/CFT correspondence.


2016 ◽  
Vol 25 (04) ◽  
pp. 1650043 ◽  
Author(s):  
Ciprian A. Sporea ◽  
Andrzej Borowiec

In this paper, we are discussing the problem of low energy greybody factors for fermions emitted by a Schwarzschild-de Sitter (SdS) black hole. In our study, we are using the analytical methods proposed by Unruh some time ago for determining the greybody factors. We have found that at low energies the greybody factors are constant for a given total angular momentum (similar to what happens in the case of scalar particles reported before in the literature). Also, our results are indicating an enhancement in the energy spectrum if one is increasing the value of the cosmological constant. These results are consistent with numerical calculations performed by S. F. Wu et al., Phys. Rev. D 78 (1998) 084010.


2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Alejandra Castro ◽  
Victor Godet ◽  
Finn Larsen ◽  
Yangwenxiao Zeng

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