scholarly journals Thermodynamics of Schwarzschild–Beltrami–de Sitter black hole

2017 ◽  
Vol 32 (27) ◽  
pp. 1750146 ◽  
Author(s):  
Hang Liu ◽  
Xin-He Meng

In this paper, we investigate the thermodynamical properties of Schwarzschild–Beltrami–de Sitter (S–BdS) black hole introduced by Yan et al. in 2013 by introducing inertial Beltrami coordinates to traditional non-inertial Schwarzschild–de Sitter (S–dS) metric which is the exact static spherical symmetry solution of Einstein equation with a positive cosmological constant [Formula: see text]. Based on this new metric, we compute entropy on all horizons and we give the entropy bound of the black hole. Hawking temperatures are calculated by considering a perturbation to entropy relations due to that the spacetime described by these inertial coordinates is no longer a stationary spacetime in which surface gravity related to Hawking temperature is defined well on killing horizon. We also get the Smarr relations and the first law of thermodynamics. We find that the S–BdS black hole seems to have similar thermodynamical properties to S–dS black hole in the comparison between their corresponding thermodynamical quantities, although the new black hole metric is described by inertial coordinates which exclude the effects of inertial force.

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Juan Maldacena ◽  
Gustavo J. Turiaci ◽  
Zhenbin Yang

Abstract We study some aspects of the de Sitter version of Jackiw-Teitelboim gravity. Though we do not have propagating gravitons, we have a boundary mode when we compute observables with a fixed dilaton and metric at the boundary. We compute the no-boundary wavefunctions and probability measures to all orders in perturbation theory. We also discuss contributions from different topologies, borrowing recent results by Saad, Shenker and Stanford. We discuss how the boundary mode leads to gravitational corrections to cosmological observables when we add matter. Finally, starting from a four dimensional gravity theory with a positive cosmological constant, we consider a nearly extremal black hole and argue that some observables are dominated by the two dimensional nearly de Sitter gravity dynamics.


2017 ◽  
Vol 26 (09) ◽  
pp. 1750100 ◽  
Author(s):  
Sharmanthie Fernando ◽  
Amanda Manning

The main purpose of this paper is to study quasinormal modes (QNM) of a black hole in massive gravity with a positive cosmological constant due to electromagnetic perturbations. A detailed study of the QNM frequencies for the electromagnetic field is done by varying the parameters of the theory such as the mass, scalar charge, cosmological constant, and the spherical harmonic index. We have employed the sixth-order WKB approximation to calculate the QNM frequencies. The electromagnetic potential for the near extreme massive gravity de Sitter black hole is approximated with the Pöschl–Teller potential to obtain exact frequencies. The null geodesics of the black hole in massive gravity is employed to describe the absorption cross-sections at high-frequency limit.


2002 ◽  
Vol 17 (06n07) ◽  
pp. 829-832 ◽  
Author(s):  
REMO GARATTINI

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.


2006 ◽  
Vol 21 (27) ◽  
pp. 2043-2054 ◽  
Author(s):  
YVES BRIHAYE ◽  
TERENCE DELSATE

Numerical arguments are presented for the existence of regular and black hole solutions of the Einstein–Skyrme equations with a positive cosmological constant. These classical configurations approach asymptotically the de Sitter spacetime. The main properties of the solutions and the differences with respect to the asymptotically flat ones are discussed. In particular our results suggest that, for a positive cosmological constant, the mass evaluated as timelike infinity in infinite. Special emphasis is set to de Sitter black holes Skyrmions which display two horizons.


2019 ◽  
Vol 34 (28) ◽  
pp. 1950158 ◽  
Author(s):  
B. Pourhassan ◽  
H. Farahani ◽  
S. Upadhyay

In this paper, we consider higher-order correction of the entropy and study the thermodynamical properties of recently proposed Schwarzschild–Beltrami–de Sitter black hole, which is indeed an exact solution of Einstein equation with a positive cosmological constant. By using the corrected entropy and Hawking temperature, we extract some thermodynamical quantities like Gibbs and Helmholtz free energies and heat capacity. We also investigate the first and second laws of thermodynamics. We find that presence of higher-order corrections, which come from thermal fluctuations, may remove some instabilities of the black hole. Also unstable to stable phase transition is possible in presence of the first- and second-order corrections.


2018 ◽  
Vol 27 (04) ◽  
pp. 1850046 ◽  
Author(s):  
Xiaokai He ◽  
Jiliang Jing ◽  
Zhoujian Cao

Gravitational radiation plays an important role in astrophysics. Based on the fact that our universe is expanding, the gravitational radiation when a positive cosmological constant is presented has been studied along with two different ways recently, one is the Bondi–Sachs (BS) framework in which the result is shown by BS quantities in the asymptotic null structure, the other is the perturbation approach in which the result is presented by the quadrupoles of source. Therefore, it is worth to interpret the quantities in asymptotic null structure in terms of the information of the source. In this paper, we investigate this problem and find the explicit expressions of BS quantities in terms of the quadrupoles of source in asymptotically de Sitter spacetime. We also estimate how far away the source is, the cosmological constant may affect the detection of the gravitational wave.


2018 ◽  
Vol 27 (04) ◽  
pp. 1850048
Author(s):  
Xudong Meng ◽  
Ruihong Wang

We study the thermodynamic properties of the black hole derived in Hořava–Lifshitz (HL) gravity without the detailed-balance condition. The parameter [Formula: see text] in the HL black hole plays the same role as that of the electric charge in the Reissner–Nordström-anti-de Sitter (RN-AdS) black hole. By analogy, we treat the parameter [Formula: see text] as the thermodynamic variable and obtain the first law of thermodynamics for the HL black hole. Although the HL black hole and the RN-AdS black hole have the similar mass and temperature, due to their very different entropy, the two black holes have very different thermodynamic properties. By calculating the heat capacity and the free energy, we analyze the thermodynamic stability of the HL black hole.


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