scholarly journals Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
K. L. Duggal
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Space Time ◽  
Time Dependent ◽  
New Technique ◽  
Open Problems ◽  
Totally Umbilical ◽  
Kinematic Condition ◽  
A New Technique

A new technique is used to study a family of time-dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson-Walker (GRW) space-time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1+n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in (M¯,g¯). Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems.

scholarly journals THE MILNE SPACETIME AND THE HADRONIC RINDLER HORIZON

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1379-1384 ◽  
Author(s):  
H. CULETU
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Time Dependent ◽  
Anisotropic Fluid ◽  
Direct Relation ◽  
Schwarzschild Black Hole ◽  
Black Hole Interior ◽  
Flat Metric ◽  
Shear Tensor ◽  
Hadronic Rindler Horizon

A direct relation between the time-dependent Milne geometry and the Rindler spacetime is shown. Milne's metric corresponds to the region beyond Rindler's event horizon (in the wedge t ≻ |x|). We point out that inside a Schwarzschild black hole and near its horizon, the metric may be Milne's flat metric. It was found that the shear tensor associated to a congruence of fluid particles of the RHIC expanding fireball has the same structure as that corresponding to the anisotropic fluid from the black hole interior, even though the latter geometry is curved.

scholarly journals Quantum-Gravitational Trans-Planckian Energy of a Time-Dependent Black Hole

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1303
Author(s):  
A. J. Nurmagambetov ◽  
I. Y. Park
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Black Hole Solution ◽  
Energy Analysis ◽  
Scaling Behavior ◽  
Time Dependent ◽  
Higgs Potential ◽  
Rotating Black Hole ◽  
Basic Features

We continue our recent endeavor in which a time-dependent black hole solution of a one-loop quantum-corrected Einstein-scalar system was obtained and its near-horizon behavior was analyzed. The energy analysis led to a trans-Planckian scaling behavior near the event horizon. In the present work, the analysis is extended to a rotating black hole solution of an Einstein–Maxwell-scalar system with a Higgs potential. Although the analysis becomes much more complex compared to that of the previous, we observe the same basic features, including the quantum-gravitational trans-Planckian energy near the horizon.

scholarly journals Bowen Fluorescence from Companion Stars in X-Ray Binaries

2004 ◽  
Vol 194 ◽  
pp. 21-22
Author(s):  
J. Casares ◽  
D. Steeghs ◽  
R. I. Hynes ◽  
P. A. Charles ◽  
R. Cornelisse ◽  
...  
Keyword(s):  
Black Hole ◽  
New Technique ◽  
X Ray ◽  
Preliminary Results ◽  
A New Technique ◽  
X Ray Binaries ◽  
Mass Functions

AbstractThis paper will review a new technique of detecting companion stars in LMXBs and X-ray transients in outburst using the Bowen fluorescence NIII lines at 4634-4640. These lines are very efficiently reprocessed in the atmospheres of the companion stars and, thereby, provide estimates of the K2 velocities and mass functions. The method has been applied to Sco X-1, X1822-371 and GX339-4 which, in the latter case, provides dynamical evidence for the presence of an accreting black hole. Preliminary results from a VLT campaign on V801 Ara, V926 Sco and XTE J1814-338 are also presented.

scholarly journals The Accurate Modification of Tunneling Radiation of Fermions with Arbitrary Spin in Kerr-de Sitter Black Hole Space-Time

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Bei Sha ◽  
Zhi-E Liu ◽  
Xia Tan ◽  
Yu-Zhen Liu ◽  
Jie Zhang
Keyword(s):  
Black Hole ◽  
Dispersion Relation ◽  
String Theory ◽  
Event Horizon ◽  
Quantum Tunneling ◽  
Gravitational Theory ◽  
Arbitrary Spin ◽  
Space Time ◽  
De Sitter ◽  
Tunneling Radiation

The quantum tunneling radiation of fermions with arbitrary spin at the event horizon of Kerr-de Sitter black hole is accurately modified by using the dispersion relation proposed in the study of string theory and quantum gravitational theory. The derived tunneling rate and temperature at the black hole horizons are analyzed and studied.

scholarly journals Time-Dependent Evolving Null Horizons of a Dynamical Spacetime

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. L. Duggal
Keyword(s):  
Black Hole ◽  
Energy Condition ◽  
Physical Models ◽  
Open Problems ◽  
Totally Umbilical ◽  
Unique Existence ◽  
Null Hypersurfaces ◽  
Isolated Horizons ◽  
Black Hole Spacetime ◽  
General Existence

Totally geodesic null hypersurfaces have been widely used in the study of isolated black holes. In this paper, we introduce a new quasilocal notion of a family of totally umbilical null hypersurfaces called evolving null horizons (ENH) of a dynamical spacetime, satisfied under an appropriate energy condition. We focus on a variety of examples of ENHs and in some cases establish their relation with event and isolated horizons. We also present two specific physical models of an ENH in a black hole spacetime. Beside the examples, for further study we propose two open problems on possible general existence of an ENH in a black hole spacetime and its canonical or unique existence. The results of this paper have ample scope of working on totally umbilical null hypersurfaces of Lorentzian and, in general, semiRiemannian manifolds.

AN ANSWER TO THE MAIN BLACK HOLE PATHOLOGY: FORMING NONSINGULAR BLACK HOLES FROM DUST COLLAPSE

2009 ◽  
Vol 18 (14) ◽  
pp. 2221-2229 ◽  
Author(s):  
R. MAIER ◽  
I. DAMIÃO SOARES
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Event Horizon ◽  
Nonlinear Resonance ◽  
Space Time ◽  
Low Energy ◽  
Spherically Symmetric ◽  
Energy Limit ◽  
Exterior Space

The dynamics of gravitational collapse is examined in the realm of string-based formalism of D-branes which encompasses general relativity as a low energy limit. A complete analytical solution is given to the spherically symmetric collapse of a pure dust star, including its matching with a corrected Schwarzschild exterior space–time. The collapse forms a black hole (an exterior event horizon) enclosing not a singularity but perpetually bouncing matter in the infinite chain of space–time maximal analytical extensions inside the outer event horizon. This chain of analytical extensions has a structure analogous to that of the Reissner–Nordstrom solution. The interior trapped bouncing matter has the possibility of being expelled by disruptive nonlinear resonance mechanisms.

Local matching of random restriction maps

2001 ◽  
Vol 38 (02) ◽  
pp. 335-356 ◽  
Author(s):  
Mengxiang Tang ◽  
Michael S. Waterman
Keyword(s):  
Restriction Fragment ◽  
Statistical Significance ◽  
Poisson Approximation ◽  
New Technique ◽  
Restriction Maps ◽  
Open Problems ◽  
Dna Restriction ◽  
A New Technique ◽  
Stein Method ◽  
Random Restriction

Optical mapping is a new technique to generate restriction maps of DNA easily and quickly. DNA restriction maps can be aligned by comparing corresponding restriction fragment lengths. To relate, organize, and analyse these maps it is necessary to rapidly compare maps. The issue of the statistical significance of approximately matching maps then becomes central, as in BLAST with sequence scoring. In this paper, we study the approximation to the distribution of counts of matched regions of specified length when comparing two DNA restriction maps. Distributional results are given to enable us to compute p-values and hence to determine whether or not the two restriction maps are related. The key tool used is the Chen-Stein method of Poisson approximation. Certain open problems are described.

A new technique to determine rate constants for growth and agglomeration with size- and time-dependent nuclei formation

2006 ◽  
Vol 61 (1) ◽  
pp. 282-292 ◽  
Author(s):  
Mirko Peglow ◽  
Jitendra Kumar ◽  
Gerald Warnecke ◽  
Stefan Heinrich ◽  
Lothar Mörl
Keyword(s):  
Rate Constants ◽  
Time Dependent ◽  
New Technique ◽  
A New Technique

scholarly journals Quantum-Gravitational Trans-Planckian Energy of a Time-Dependent Black Hole

2019 ◽  
Author(s):  
A. J. Nurmagambetov ◽  
I. Y. Park
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Black Hole Solution ◽  
Energy Analysis ◽  
Scaling Behavior ◽  
Time Dependent ◽  
Higgs Potential ◽  
Rotating Black Hole ◽  
Basic Features

We continue our recent endeavor in which a time-dependent black hole solution of a one-loop quantum-corrected Einstein-scalar system was obtained and its near-horizon behavior was analyzed. The energy analysis led to a trans-Planckian scaling behavior near the event horizon. In the present work the analysis is extended to a rotating black hole solution of an Einstein-Maxwell-scalar system with a Higgs potential. Although the analysis becomes much more complex compared to that of the previous, we observe the same basic features, including the quantum-gravitational trans-Planckian energy near the horizon.

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