Black holes in de Sitter space and the stability conjecture of Cauchy horizons

1995 ◽  
Vol 52 (2) ◽  
pp. 666-671 ◽  
Author(s):  
Rong-Gen Cai ◽  
Ru-Keng Su
Keyword(s):  
Black Holes ◽  
De Sitter Space ◽  
De Sitter ◽  
Stability Conjecture ◽  
The Stability

scholarly journals CLASSICAL STABILITY OF BLACK HOLES UNDER MASSLESS DIRAC PERTURBATIONS

2012 ◽  
Vol 21 (13) ◽  
pp. 1250092 ◽  
Author(s):  
A. LÓPEZ-ORTEGA
Keyword(s):  
Black Holes ◽  
Positive Definite ◽  
Dirac Field ◽  
De Sitter ◽  
Deformation Method ◽  
Effective Potentials ◽  
Classical Stability ◽  
Region Exterior ◽  
Classical Fields ◽  
The Stability

In a D-dimensional maximally symmetric spacetime we simplify the massless Dirac equation to two decoupled wavelike equations with effective potentials. Furthermore in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes we note that for the massless Dirac field moving in the region exterior to the event horizon at least one of the effective potentials is not positive definite. Therefore the classical stability of these black holes against this field is not guaranteed. Here with the help of the S-deformation method, we state their classical stability against the massless Dirac field, extend these results to maximally symmetric black holes and comment on the applicability of our results to establish the stability with respect to other classical fields.

Thermodynamic geometry of charged dilaton black holes in AdS spaces

2016 ◽  
Vol 94 (10) ◽  
pp. 1045-1053 ◽  
Author(s):  
Ahmad Sheykhi ◽  
Seyed Hossein Hendi ◽  
Fatemeh Naeimipour ◽  
Shahram Panahiyan ◽  
Behzad Eslam Panah
Keyword(s):  
Black Holes ◽  
Ricci Scalar ◽  
Thermodynamic Quantities ◽  
Geometrical Approach ◽  
De Sitter ◽  
Ads Black Holes ◽  
Divergence Points ◽  
The Stability ◽  
Thermodynamical Behavior ◽  
Dilaton Black Holes

It was shown that with the combination of three Liouville-type dilaton potentials, one can derive dilaton black holes in the background of anti-de-Sitter (AdS) spaces. In this paper, we further extend the study on the dilaton AdS black holes by investigating their thermodynamic instability through a geometry approach. First, we review thermodynamic quantities of the solutions and check the validity of the first law of thermodynamics. Then, we investigate phase transitions and stability of the solutions. In particular, we disclose the effects of the dilaton field on the stability of the black holes. We also employ the geometrical approach toward thermodynamical behavior of the system and find that the divergencies in the Ricci scalar coincide with roots and divergencies in the heat capacity. We find that the behavior of the Ricci scalar around divergence points depends on the type of the phase transition.

scholarly journals Phase Transition and Entropy Force between Two Horizons in (n+2)-Dimensional de Sitter Space

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yang Zhang ◽  
Wen-qi Wang ◽  
Yu-bo Ma ◽  
Jun Wang
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Physical Mechanism ◽  
De Sitter Space ◽  
Space Time ◽  
Thermodynamic Quantities ◽  
De Sitter ◽  
Time Dimension ◽  
Cosmic Expansion

In this paper, the effect of the space-time dimension on effective thermodynamic quantities in (n+2)-dimensional Reissner-Nordstrom-de Sitter space has been studied. Based on derived effective thermodynamic quantities, conditions for the phase transition are obtained. The result shows that the accelerating cosmic expansion can be attained by the entropy force arisen from the interaction between horizons of black holes and our universe, which provides a possible way to explain the physical mechanism for the accelerating cosmic expansion.

scholarly journals Anti-de Sitter space and black holes

1998 ◽  
Vol 15 (11) ◽  
pp. 3575-3598 ◽  
Author(s):  
Máximo Bañados ◽  
Andrés Gomberoff ◽  
Cristián Martínez
Keyword(s):  
Black Holes ◽  
De Sitter Space ◽  
De Sitter

A de-Sitter weak gravity conjecture

2021 ◽  
Author(s):  
Ignatios Antoniadis ◽  
Karim Benakli
Keyword(s):  
Black Holes ◽  
Mass Formula ◽  
Flat Space ◽  
De Sitter Space ◽  
Large Radius ◽  
De Sitter ◽  
Time Result ◽  
A Charge ◽  
Weak Gravity ◽  
Charge Formula

The study of de-Sitter Reissner–Nordstrøm black holes allows us to uncover a Weak Gravity Conjecture in de-Sitter space. It states that for a given mass [Formula: see text] there should be a state with a charge [Formula: see text] bigger than a minimal value [Formula: see text], depending on the mass and the de-Sitter radius [Formula: see text], in Planck units. This reproduces the well-known flat space–time result [Formula: see text] in the large radius limit (large [Formula: see text]). In the highly curved de-Sitter space, ([Formula: see text]) [Formula: see text] behaves as [Formula: see text]. Finally, we discuss the case of backgrounds from gauged R-symmetry in [Formula: see text] supergravity. This paper is based on [I. Antoniadis and K. Benakli, Fortsch. Phys. 68, 2000054 (2020), arXiv:2006.12512 [hep-th]].

Thin-shell wormhole from ABGB–de Sitter black holes

2021 ◽  
pp. 2150085
Author(s):  
Nilofar Rahman ◽  
Masum Murshid ◽  
Mehedi Kalam
Keyword(s):  
Black Holes ◽  
Surface Stress ◽  
Thin Shell ◽  
Exotic Matter ◽  
Linear Perturbation ◽  
De Sitter ◽  
Wormhole Solution ◽  
The Stability ◽  
De Sitter Universe ◽  
Charge Formula

A thin shell wormhole is constructed utilizing the cut and paste technique from ABGB–de Sitter black hole derived by Matyjasek et al. The surface stress localized at the wormhole throat is determined using Darmois–Israel formalism. We examine the attractive and repulsive nature of the thin shell wormhole on which cosmological constant [Formula: see text] has a significant effect. For the fixed values of charge [Formula: see text] and mass [Formula: see text], the attractiveness of the wormhole decreases with increasing [Formula: see text]. We calculate the total amount of exotic matter in the shell, which is not much affected by [Formula: see text]. For the construction of the wormhole in de Sitter universe, the regular black holes have to be heavily charged with a light mass to minimize the amount of required exotic matter. The stability of the wormhole solution is explored by considering a general equation of state in the form of linear perturbation. The stability regions are shown in the figures.

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