Timelike limit surfaces, apparent horizons and event horizons of radiating Kerr-Newman-de Sitter black holes, inflation and cosmic censorship

1999 ◽  
Vol 16 (2) ◽  
pp. 343-350 ◽  
Author(s):  
Dian-Yan Xu
Keyword(s):  
Black Holes ◽  
Cosmic Censorship ◽  
De Sitter ◽  
Event Horizons ◽  
Apparent Horizons

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 HIGHER DIMENSIONAL INHOMOGENEOUS DUST COLLAPSE AND COSMIC CENSORSHIP

2002 ◽  
Vol 17 (20) ◽  
pp. 2747-2747
Author(s):  
A. BEESHAM
Keyword(s):  
Black Holes ◽  
Cosmic Censorship ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Naked Singularities ◽  
Singularity Theorems ◽  
Sitter Spacetime ◽  
Higher Dimensional ◽  
Cosmic Censorship Hypothesis ◽  
Strong Curvature

The singularity theorems of general relativity predict that gravitational collapse finally ends up in a spacetime singularity1. The cosmic censorship hypothesis (CCH) states that such a singularity is covered by an event horizon2. Despite much effort, there is no rigorous formulation or proof of the CCH. In view of this, examples that appear to violate the CCH and lead to naked singularities, in which non-spacelike curves can emerge, rather than black holes, are important to shed more light on the issue. We have studied several collapse scenarios which can lead to both situations3. In the case of the Vaidya-de Sitter spacetime4, we have shown that the naked singularities that arise are of the strong curvature type. Both types of singularities can also arise in higher dimensional Vaidya and Tolman-Bondi spacetimes, but black holes are favoured in some sense by the higher dimensions. The charged Vaidya-de Sitter spacetime also exhibits both types of singularities5.

The effect of dark matter on the weak cosmic censorship conjecture in the extended space

2021 ◽  
pp. 2150207
Author(s):  
Zi-Yu Fu ◽  
Bao-Qi Zhang ◽  
Chuan-Yin Wang ◽  
Hui-Ling Li
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Second Law Of Thermodynamics ◽  
Cosmic Censorship ◽  
De Sitter ◽  
Extended Phase ◽  
Extended Space ◽  
Extreme Black Holes ◽  
Cosmic Censorship Conjecture

By analyzing the energy–momentum relationship of the absorbed fermions dropping into a Reissner–Nordstöm–anti-de Sitter black hole surrounded by dark matter, the laws of thermodynamic and weak cosmic censorship conjecture in the extended phase space are investigated. We find that the first law of thermodynamics is valid. However, the validity of the second law of thermodynamics depends on the density [Formula: see text] of the perfect fluid dark matter. In addition, we also find that when the fermions are absorbed, the structures of black hole surrounded by dark matter would not change. Therefore, weak cosmic censorship conjecture holds for the extreme black holes and the non-extreme black holes.

scholarly journals Strong cosmic censorship under quasinormal modes of non-minimally coupled massive scalar field

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Bogeun Gwak
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Decay Rate ◽  
Small Mass ◽  
Cosmic Censorship ◽  
Massive Scalar ◽  
De Sitter ◽  
Massive Scalar Field ◽  
Strong Cosmic Censorship ◽  
Cosmic Censorship Conjecture

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.

scholarly journals NONSTATIC CHARGED BTZ-LIKE BLACK HOLES IN N+1 DIMENSIONS

2012 ◽  
Vol 21 (03) ◽  
pp. 1250022 ◽  
Author(s):  
SUSHANT G. GHOSH
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Collapse ◽  
Naked Singularity ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Btz Black Hole ◽  
Sitter Spacetime ◽  
Apparent Horizons ◽  
Sitter Background

We find an exact nonstatic charged BTZ-like solutions, in (N+1)-dimensional Einstein gravity in the presence of negative cosmological constant and a nonlinear Maxwell field defined by a power s of the Maxwell invariant, which describes the gravitational collapse of charged null fluid in an anti-de Sitter background. Considering the situation that a charged null fluid injects into the initially an anti-de Sitter spacetime, we show that a black hole form rather than a naked singularity, irrespective of spacetime dimensions, from gravitational collapse in accordance with cosmic censorship conjecture. The structure and locations of the apparent horizons of the black holes are also determined. It is interesting to see that, in the static limit and when N = 2, one can retrieve 2+1 BTZ black hole solutions.

scholarly journals Fermions tunneling from charged anti-de Sitter black holes

2012 ◽  
Vol 90 (9) ◽  
pp. 903-909 ◽  
Author(s):  
Muhammad Sharif ◽  
Wajiha Javed
Keyword(s):  
Black Holes ◽  
Dirac Equation ◽  
Cosmological Constant ◽  
Hawking Radiation ◽  
Charged Particles ◽  
De Sitter ◽  
Event Horizons ◽  
Horizon Radius ◽  
Fermions Tunneling ◽  
Dilaton Black Holes

We study Hawking radiation as a phenomenon of tunneling through event horizons of charged torus-like as well as dilaton black holes involving a cosmological constant based on Kerner and Mann’s formulation. We obtain tunneling probabilities as well as Hawking’s emission temperature of outgoing charged particles by applying the semiclassical Wentzel–Kramers–Brillouin approximation to the general covariant Dirac equation. The graphical behavior of Hawking temperature and horizon radius is investigated. We find results consistent with those already given in the literature.

scholarly journals NONSPHERICAL COLLAPSE OF TWO-FLUID STAR

2008 ◽  
Vol 23 (25) ◽  
pp. 4245-4254 ◽  
Author(s):  
S. G. GHOSH
Keyword(s):  
Black Holes ◽  
Equation Of State ◽  
Naked Singularity ◽  
De Sitter Space ◽  
Cosmic Censorship ◽  
De Sitter ◽  
Plane Symmetric ◽  
Cylindrically Symmetric ◽  
Hoop Conjecture ◽  
Two Fluid

We obtain the analog of collapsing Vaidya-like solution to include both a null fluid and a string fluid, with a linear equation of state (p⊥ = kρ), in nonspherical (plane symmetric and cylindrically symmetric) anti-de Sitter space–times. It turns out that the nonspherical collapse of two fluid in anti-de Sitter space–times, in accordance with cosmic censorship, proceed to form black holes, i.e. on naked singularity ever forms, in accordance with cosmic censorship, violating hoop conjecture.

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