scholarly journals Thermodynamics of de Sitter black holes with a conformally coupled scalar field

2005 ◽  
Vol 72 (2) ◽  
Author(s):  
Anne-Marie Barlow ◽  
Daniel Doherty ◽  
Elizabeth Winstanley
Keyword(s):  
Author(s):  
Bogeun Gwak

Abstract We investigate the strong cosmic censorship conjecture in lukewarm Reissner–Nordström–de Sitter black holes (and Martínez–Troncoso–Zanelli black holes) using the quasinormal resonance of non-minimally coupled massive scalar field. The strong cosmic censorship conjecture is closely related to the stability of the Cauchy horizon governed by the decay rate of the dominant quasinormal mode. Here, dominant modes are obtained in the limits of small and large mass black holes. Then, we connect the modes by using the WKB approximation. In our analysis, the strong cosmic censorship conjecture is valid except in the range of the small-mass limit, in which the dominant mode can be assumed to be that of the de Sitter spacetime. Particularly, the coupling constant and mass of the scalar field determine the decay rate in the small mass range. Therefore, the validity of the strong cosmic censorship conjecture depends on the characteristics of the scalar field.


2020 ◽  
Vol 29 (07) ◽  
pp. 2050048
Author(s):  
Xin-Yang Wang ◽  
Yi-Ru Wang ◽  
Wen-Biao Liu

Based on the definition of the interior volume of spherically symmetry black holes, the interior volume of Schwarzschild–(Anti) de Sitter black holes is calculated. It is shown that with the cosmological constant ([Formula: see text]) increasing, the changing behaviors of both the position of the largest hypersurface and the interior volume for the Schwarzschild–Anti de Sitter black hole are the same as the Schwarzschild–de Sitter black hole. Considering a scalar field in the interior volume and Hawking radiation with only energy, the evolution relation between the scalar field entropy and Bekenstein–Hawking entropy is constructed. The results show that the scalar field entropy is approximately proportional to Bekenstein–Hawking entropy during Hawking radiation. Meanwhile, the proportionality coefficient is also regarded as a constant approximately with the increasing [Formula: see text]. Furthermore, considering [Formula: see text] as a dynamical variable, the modified Stefan–Boltzmann law is proposed which can be used to describe the variation of both the mass and [Formula: see text] under Hawking radiation. Using this modified law, the evolution relation between the two types of entropy is also constructed. The results show that the coefficient for Schwarzschild–de Sitter black holes is closer to a constant than the one for Schwarzschild–Anti de Sitter black holes during the evaporation process. Moreover, we find that for Hawking radiation carrying only energy, the evolution relation is a special case compared with the situation that the mass and [Formula: see text] are both considered as dynamical variables.


2002 ◽  
Vol 17 (20) ◽  
pp. 2767-2767
Author(s):  
JOSÉ P. S. LEMOS ◽  
VITOR CARDOSO

In the context of the AdS/CFT conjecture1, a Schwarzschild-anti-de Sitter (SAdS) black hole may be looked at as a thermal state in the CFT. Perturbing the black hole corresponds in the CFT to perturb the thermal state. We considered an important specific perturbation - the radial infall of a small test particle coupled to a scalar field into a SAdS black hole. We computed the spectra, waveforms and total scalar energy radiated during this process. For small black holes, the spectra is dominated by a resonance, and the waveform by quasinormal ringing2,3,4. For large black holes we find that the waveform quickly settles down to its final zero value, always in a quasinormal way. The approach to thermal equilibrium in the CFT is therefore dictated by the lowest quasinormal frequency. We also commented on the interpretation of the bulk process when viewed from the brane: to the black hole corresponds a thermal bath, to the infalling probe corresponds an expanding bubble, and to the scalar field waves correspond particles decaying into bosons of the associate operator of the gauge theory. For more details see5,6.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Davide Astesiano ◽  
S.L. Cacciatori

Abstract We find a new non BPS solution in N = 2 D = 4 gauged supergravity coupled to U(1) gauge fields and matter. It consists in a closed universe with two extremal black holes of equal size, surrounding two singularities. They have opposite magnetic charges (and no electric charges), but stay in static equilibrium thanks to the positive pressure of a cosmological constant. The geometry is perfectly symmetric under the exchange of the black holes and the flip of the sign of the charges. However the scalar field is non constant and non symmetric, with different values at the horizons, which depend on a real modulus. Remarkably we show that it satisfies the attractor mechanism and the entropy indeed depends only on the magnetic charges. At one of the horizons the solution becomes $$ \frac{1}{2} $$ 1 2 -BPS supersymmetric, while at the other one there is no supersymmetry, but the entropy remains independent from the scalar modulus.


2001 ◽  
Vol 10 (06) ◽  
pp. 807-809 ◽  
Author(s):  
SAURYA DAS ◽  
J. GEGENBERG ◽  
V. HUSAIN

We investigate thermodynamic properties of two types of asymptotically anti-de Sitter spacetimes: black holes and singular scalar field spacetimes. We describe the possibility that thermodynamic phase transitions can transform one spacetime into another, suggesting that black holes can radiate to naked singularities.


2010 ◽  
Vol 2010 (11) ◽  
Author(s):  
Óscar J. C. Dias ◽  
Ricardo Monteiro ◽  
Harvey S. Reall ◽  
Jorge E. Santos
Keyword(s):  

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Almendra Aragón ◽  
P.A. González ◽  
Eleftherios Papantonopoulos ◽  
Yerko Vásquez

Abstract Recently an anomalous decay rate of the quasinormal modes of a massive scalar field in Schwarzschild black holes backgrounds was reported in which the longest-lived modes are the ones with higher angular number, for a scalar field mass smaller than a critical value, while that beyond this value the behaviour is inverted. In this work, we extend the study to other asymptotic geometries, such as, Schwarzschild-de Sitter and Schwarzschild-AdS black holes. Mainly, we found that such behaviour and the critical mass are present in the Schwarzschild-de Sitter background. Also, we found that the value of the critical mass increases when the cosmological constant increases and also when the overtone number is increasing. On the other hand, despite the critical mass is not present in Schwarzschild-AdS black holes backgrounds, the decay rate of the quasinormal modes always exhibits an anomalous behaviour.


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