scholarly journals The fate of Schwarzschild–de Sitter black holes in f(R) gravity

2016 ◽  
Vol 31 (09) ◽  
pp. 1650054 ◽  
Author(s):  
Andrea Addazi ◽  
Salvatore Capozziello
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Thermal Radiation ◽  
Black Hole Physics ◽  
Black Hole Horizon ◽  
De Sitter ◽  
Trapped Surfaces ◽  
Emission Time ◽  
Marginally Trapped Surfaces

The semiclassical effects of anti-evaporating black holes can be discussed in the framework of f(R) gravity. In particular, the Bousso–Hawking–Nojiri–Odinstov anti-evaporation instability of degenerate Schwarzschild–de Sitter black holes (the so-called Nariai spacetime) leads to a dynamical increasing of black hole horizon in f(R) gravity. This phenomenon causes the following transition: emitting marginally trapped surfaces (TS) become space-like surfaces before the effective Bekenstein–Hawking emission time. As a consequence, Bousso–Hawking thermal radiation cannot be emitted in an anti-evaporating Nariai black hole. Possible implications in cosmology and black hole physics are also discussed.

scholarly journals On the Trapped Surface Characterization of Black Hole Region in Vaidya Spacetime

2018 ◽  
Vol 10 (1) ◽  
pp. 59
Author(s):  
Mohammed Kumah ◽  
Francis T. Oduro
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Surface Characterization ◽  
Local Approach ◽  
Null Infinity ◽  
Trapped Surfaces ◽  
Marginally Trapped Surfaces ◽  
Trapped Surface

Characterizing black holes by means of classical event horizon is a global concept because it depends on future null infinity. This means, to find black hole region and event horizon requires the notion of the entire spacetime which is a teleological concept. With this as a motivation, we use local approach as a complementary means of characterizing black holes. In this paper we apply Gauss divergence and covariant divergence theorems to compute the fluxes and the divergences of the appropriate null vectors in Vaidya spacetime and thus explicitly determine the existence of trapped and marginally trapped surfaces in its black hole region.

scholarly journals Phase transitions and entropy force of charged de Sitter black holes with cloud of string and quintessence

2020 ◽  
Vol 29 (15) ◽  
pp. 2050108
Author(s):  
Yubo Ma ◽  
Yang Zhang ◽  
Ren Zhao ◽  
Shuo Cao ◽  
Tonghua Liu ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Phase Transitions ◽  
Black Hole Horizon ◽  
Thermodynamic Quantities ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Lennard Jones ◽  
First Order Phase Transition ◽  
First Order Phase

In this paper, we investigate the combined effects of the cloud of strings and quintessence on the thermodynamics of a Reissner–Nordström–de Sitter black hole. Based on the equivalent thermodynamic quantities considering the correlation between the black hole horizon and the cosmological horizon, we extensively discuss the phase transitions of the spacetime. Our analysis proves that similar to the case in AdS spacetime, second-order phase transitions could take place under certain conditions, with the absence of first-order phase transition in the charged de Sitter (dS) black holes with cloud of string and quintessence. The effects of different thermodynamic quantities on the phase transitions are also quantitatively discussed, which provides a new approach to study the thermodynamic qualities of unstable dS spacetime. Focusing on the entropy force generated by the interaction between the black hole horizon and the cosmological horizon, as well as the Lennard–Jones force between two particles, our results demonstrate the strong degeneracy between the entropy force of the two horizons and the ratio of the horizon positions, which follows the surprisingly similar law given the relation between the Lennard–Jones force and the ratio of two particle positions. Therefore, the study of the entropy force between two horizons is not only beneficial to the deep exploration of the three modes of cosmic evolution, but also helpful to understand the correlation between the microstates of particles in black holes and those in ordinary thermodynamic systems.

scholarly journals Introducing the inverse hoop conjecture for black holes

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Shahar Hod
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Surface Area ◽  
Black Hole Horizon ◽  
De Sitter ◽  
Hoop Conjecture

AbstractIt is conjectured that stationary black holes are characterized by the inverse hoop relation $${\mathcal {A}}\le {\mathcal {C}}^2/\pi $$ A ≤ C 2 / π , where $${\mathcal {A}}$$ A and $${\mathcal {C}}$$ C are respectively the black-hole surface area and the circumference length of the smallest ring that can engulf the black-hole horizon in every direction. We explicitly prove that generic Kerr–Newman–(anti)-de Sitter black holes conform to this conjectured area-circumference relation.

scholarly journals Quantum information versus black hole physics: deep firewalls from narrow assumptions

2018 ◽  
Vol 376 (2123) ◽  
pp. 20170324 ◽  
Author(s):  
Samuel L. Braunstein ◽  
Stefano Pirandola
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Physics ◽  
Foundations Of Quantum Mechanics ◽  
Contemporary Society ◽  
De Sitter ◽  
Original Surface ◽  
Thermodynamic Entropy ◽  
Initial Onset ◽  
Real Phenomenon

The prevalent view that evaporating black holes should simply be smaller black holes has been challenged by the firewall paradox. In particular, this paradox suggests that something different occurs once a black hole has evaporated to one-half its original surface area. Here, we derive variations of the firewall paradox by tracking the thermodynamic entropy within a black hole across its entire lifetime and extend it even to anti-de Sitter space–times. Our approach sweeps away many unnecessary assumptions, allowing us to demonstrate a paradox exists even after its initial onset (when conventional assumptions render earlier analyses invalid). The most natural resolution may be to accept firewalls as a real phenomenon. Further, the vast entropy accumulated implies a deep firewall that goes ‘all the way down’ in contrast with earlier work describing only a structure at the horizon. This article is part of a discussion meeting issue ‘Foundations of quantum mechanics and their impact on contemporary society’.

scholarly journals Phase transition and entropic force of de Sitter black hole in massive gravity

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Yubo Ma ◽  
Yang Zhang ◽  
Lichun Zhang ◽  
Liang Wu ◽  
Ying Gao ◽  
...  
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Massive Gravity ◽  
Space Time ◽  
Black Hole Horizon ◽  
Thermodynamic Quantities ◽  
Cosmological Horizon ◽  
Entropic Force ◽  
De Sitter

AbstractIt is well known that de Sitter(dS) black holes generally have a black hole horizon and a cosmological horizon, both of which have Hawking radiation. But the radiation temperature of the two horizons is generally different, so dS black holes do not meet the requirements of thermal equilibrium stability, which brings certain difficulties to the study of the thermodynamic characteristics of black holes. In this paper, dS black hole is regarded as a thermodynamic system, and the effective thermodynamic quantities of the system are obtained. The influence of various state parameters on the effective thermodynamic quantities in the massive gravity space-time is discussed. The condition of the phase transition of the de Sitter black hole in massive gravity space-time is given. We consider that the total entropy of the dS black hole is the sum of the corresponding entropy of the two horizons plus an extra term from the correlation of the two horizons. By comparing the entropic force of interaction between black hole horizon and the cosmological horizon with Lennard-Jones force between two particles, we find that the change rule of entropic force between the two system is surprisingly the same. The research will help us to explore the real reason of accelerating expansion of the universe.

scholarly journals CAN BLACK HOLES BE CREATED AT THE BIRTH OF THE UNIVERSE?

1999 ◽  
Vol 14 (34) ◽  
pp. 2403-2408 ◽  
Author(s):  
ZHONG CHAO WU
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
De Sitter Space ◽  
Black Hole Horizon ◽  
De Sitter ◽  
The Family ◽  
The Creation ◽  
The Universe ◽  
Entropy Of The Universe

We study the quantum creation of black hole pairs in the (anti-)de Sitter space background. These black hole pairs in the Kerr–Newman family are created from constrained instantons. At the WKB level, for the chargeless and nonrotating case, the relative creation probability is the exponential of (the negative of) the entropy of the universe. Also for the remaining cases of the family, the creation probability is the exponential of (the negative of) one quarter of the sum of the inner and outer black hole horizon areas. In the absence of a general no-boundary proposal for open universes, we treat the creations of the closed and the open universes in the same way.

scholarly journals The Fundamental Roles of the de Sitter Vacuum

Universe ◽  
2020 ◽  
Vol 6 (8) ◽  
pp. 101 ◽  
Author(s):  
Irina Dymnikova
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Wide Class ◽  
Particle Physics ◽  
Black Hole Physics ◽  
Higgs Mechanism ◽  
Accelerated Expansion ◽  
De Sitter ◽  
Naked Singularities ◽  
De Sitter Vacuum

We overview the fundamental roles of the de Sitter vacuum in cosmology where it is responsible for powering the early inflationary stage(s) and the present accelerated expansion, in black hole physics where it provides the existence of a wide class of regular black holes and self-gravitating solitons replacing naked singularities, and in particle physics where it ensures the intrinsic relation of the Higgs mechanism with gravity and spacetime symmetry breaking.

scholarly journals Driven black holes: from Kolmogorov scaling to turbulent wakes

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Tomas Andrade ◽  
Christiana Pantelidou ◽  
Julian Sonner ◽  
Benjamin Withers
Keyword(s):  
Nonlinear Dynamics ◽  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Strong Field ◽  
De Sitter ◽  
Event Horizons ◽  
Binary Mergers ◽  
Tidal Deformations ◽  
Proof Of Principle

Abstract General relativity governs the nonlinear dynamics of spacetime, including black holes and their event horizons. We demonstrate that forced black hole horizons exhibit statistically steady turbulent spacetime dynamics consistent with Kolmogorov’s theory of 1941. As a proof of principle we focus on black holes in asymptotically anti-de Sitter spacetimes in a large number of dimensions, where greater analytic control is gained. We focus on cases where the effective horizon dynamics is restricted to 2+1 dimensions. We also demonstrate that tidal deformations of the horizon induce turbulent dynamics. When set in motion relative to the horizon a deformation develops a turbulent spacetime wake, indicating that turbulent spacetime dynamics may play a role in binary mergers and other strong-field phenomena.

scholarly journals Uptunneling to de Sitter

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
False Vacuum ◽  
De Sitter ◽  
Dimensional Theory ◽  
Hole Geometry ◽  
Horizon Geometry ◽  
Two Sides ◽  
Extremal Black Holes

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.

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