scholarly journals Gravitational Entropy of Black Holes and Wormholes

2011 ◽  
Vol 51 (3) ◽  
pp. 925-942 ◽  
Author(s):  
Gustavo E. Romero ◽  
Romain Thomas ◽  
Daniela Pérez
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
S. C. Ulhoa ◽  
E. P. Spaniol ◽  
R. Gomes ◽  
A. F. Santos ◽  
A. E. Santana

The Thermo Field Dynamics (TFD) formalism is used to investigate the regular black holes at finite temperature. Using the Teleparalelism Equivalent to General Relativity (TEGR), the gravitational Stefan-Boltzmann law and the gravitational Casimir effect at zero and finite temperature are calculated. In addition, the first law of thermodynamics is considered. Then, the gravitational entropy and the temperature of the event horizon of a class of regular black holes are determined.


2020 ◽  
Vol 29 (02) ◽  
pp. 2050015
Author(s):  
R. de C. Lima ◽  
José A. C. Nogales ◽  
S. H. Pereira

In this work, we study and compare the features of gravitational entropy near the throat of transversable wormholes formed by exotic matter and wormholes in galactic halos. We have verified that gravitational entropy and entropy density of these wormholes in regions near their throats are indistinguishable for objects of same throat, despite the fact that they are described by different metrics and by distinct energy–momentum tensors. We have found that the gravitational entropy density diverges near the throat for both cases, probably due to a nontrivial topology at this point, however, allowing the interesting interpretation that a maximum flux of information can be carried through the throat of these wormholes. In addition, we have found that both are endowed with an entropic behaviour similar to Hawking–Bekenstein’s entropy of nonrotating and null charge black holes.


2020 ◽  
Vol 29 (05) ◽  
pp. 2050034
Author(s):  
Sarbari Guha ◽  
Samarjit Chakraborty

In this paper, we have examined the validity of a proposed definition of gravitational entropy in the context of accelerating black hole solutions of the Einstein field equations, which represent the realistic black hole solutions. We have adopted a phenomenological approach proposed in Rudjord et al. [Phys. Scr. 77, 055901 (2008)] and expanded by Romero et al. [Int. J. Theor. Phys. 51, 925 (2012)], in which the Weyl curvature hypothesis is tested against the expressions for the gravitational entropy. Considering the [Formula: see text]-metric for the accelerating black holes, we have evaluated the gravitational entropy and the corresponding entropy density for four different types of black holes, namely, nonrotating black hole, nonrotating charged black hole, rotating black hole and rotating charged black hole. We end up by discussing the merits of such an analysis and the possible reason of failure in the particular case of rotating charged black hole and comment on the possible resolution of the problem.


2004 ◽  
Vol 13 (10) ◽  
pp. 2329-2335
Author(s):  
ANDREW CHAMBLIN ◽  
JOSHUA ERLICH

Just as gravitons can carry energy, they can also be used to transmit information. It follows that an entropy should be associated with gravitational degrees of freedom, independent of the presence or absence of black holes. In this essay, we discuss how one might count gravitational entropy given a classical gravitational field. Our suggestion is motivated by a derivation of the covariant entropy bound in which a gravitational term appears naturally.


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