scholarly journals Pair creation of higher dimensional black holes on a de Sitter background

2004 ◽  
Vol 70 (12) ◽  
Author(s):  
Óscar J. C. Dias ◽  
José P. S. Lemos
Keyword(s):  
Black Holes ◽  
Pair Creation ◽  
De Sitter ◽  
Higher Dimensional ◽  
Sitter Background

PRIMORDIAL BLACK HOLE PAIR CREATION IN R2 THEORY

1998 ◽  
Vol 13 (28) ◽  
pp. 2289-2293 ◽  
Author(s):  
B. C. PAUL ◽  
S. MUKHERJEE ◽  
G. P. SINGH ◽  
A. BEESHAM
Keyword(s):  
Black Holes ◽  
Semiclassical Approximation ◽  
Pair Creation ◽  
Quadratic Term ◽  
Inflationary Universe ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
De Sitter ◽  
Gravitational Action ◽  
Spatial Section

The probability for quantum creation of an inflationary universe with a pair of black holes has been studied in semiclassical approximation with Hartle–Hawking boundary conditions, assuming a gravitational action which includes a quadratic term in the scalar curvature αR2, α being a constant. The action of the instanton responsible for creating such a universe, with a spatial section with S1×S2 topology, is seen to be less than that of a de Sitter S3 instanton, unless α<-1/(8Λ), where Λ is the cosmological constant. Since negative α implies a classical instability, the probability for production of primordial black holes seems to be suppressd in R2-theory.

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.

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 Mechanics of higher dimensional black holes in asymptotically anti-de Sitter spacetimes

2006 ◽  
Vol 24 (3) ◽  
pp. 625-644 ◽  
Author(s):  
Abhay Ashtekar ◽  
Tomasz Pawlowski ◽  
Chris Van Den Broeck
Keyword(s):  
Black Holes ◽  
De Sitter ◽  
Higher Dimensional

scholarly journals Charged Einstein-æther black holes in n-dimensional spacetime

2019 ◽  
Vol 28 (03) ◽  
pp. 1950049 ◽  
Author(s):  
Kai Lin ◽  
Fei-Hung Ho ◽  
Wei-Liang Qian
Keyword(s):  
Black Holes ◽  
Surface Gravity ◽  
De Sitter ◽  
Killing Horizon ◽  
Dimensional Spacetime ◽  
Static Black Hole ◽  
Higher Dimensional ◽  
Large Velocity ◽  
Hyperbolic Spacetimes ◽  
Charge Formula

In this work, we investigate the [Formula: see text]-dimensional charged static black hole solutions in the Einstein-æther theory. By taking the metric parameter [Formula: see text] to be [Formula: see text], and [Formula: see text], we obtain the spherical, planar, and hyperbolic spacetimes, respectively. Three choices of the cosmological constant, [Formula: see text], [Formula: see text] and [Formula: see text], are investigated, which correspond to asymptotically de Sitter, flat and anti-de Sitter spacetimes. The obtained results show the existence of the universal horizon in higher dimensional cases which may trap any particle with arbitrarily large velocity. We analyze the horizon and the surface gravity of four- and five-dimensional black holes, and the relations between the above quantities and the electrical charge. It is shown that when the aether coefficient [Formula: see text] or the charge [Formula: see text] increases, the outer Killing horizon shrinks and approaches the universal horizon. Furthermore, the surface gravity decreases and approaches zero in the limit [Formula: see text] or [Formula: see text], where [Formula: see text] is the extreme charge. The main features of the horizon and surface gravity are found to be similar to those in [Formula: see text] case, but subtle differences are also observed.

RADIATION GENERATED BY THE INFALL OF A SCALAR PARTICLE IN A SCHWARZSCHILD–ANTI-DE SITTER BACKGROUND

2002 ◽  
Vol 17 (20) ◽  
pp. 2767-2767
Author(s):  
JOSÉ P. S. LEMOS ◽  
VITOR CARDOSO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Thermal State ◽  
Scalar Particle ◽  
Thermal Bath ◽  
De Sitter ◽  
Small Test ◽  
Sitter Background ◽  
Approach To Thermal Equilibrium

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.

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