scholarly journals COLLAPSING AND STATIC THIN MASSIVE CHARGED DUST SHELLS IN A REISSNER–NORDSTRÖM BLACK HOLE BACKGROUND IN HIGHER DIMENSIONS

2008 ◽  
Vol 23 (19) ◽  
pp. 2943-2960 ◽  
Author(s):  
SIJIE GAO ◽  
JOSÉ P. S. LEMOS
Keyword(s):  
Black Hole ◽  
Thin Shell ◽  
Rest Mass ◽  
Higher Dimensions ◽  
Space Time ◽  
Particle Accelerators ◽  
Charged Dust ◽  
Empty Interior ◽  
Gravitational Radius ◽  
Black Hole Background

The problem of a spherically symmetric charged thin shell of dust collapsing gravitationally into a charged Reissner–Nordström black hole in d space–time dimensions is studied within the theory of general relativity. Static charged shells in such a background are also analyzed. First, a derivation of the equation of motion of such a shell in a d-dimensional space–time is given. Then, a proof of the cosmic censorship conjecture in a charged collapsing framework is presented, and a useful constraint which leads to an upper bound for the rest mass of a charged shell with an empty interior is derived. It is also proved that a shell with total mass equal to charge, i.e. an extremal shell, in an empty interior, can only stay in neutral equilibrium outside its gravitational radius. This implies that it is not possible to generate a regular extremal black hole by placing an extremal dust thin shell within its own gravitational radius. Moreover, it is shown, for an empty interior, that the rest mass of the shell is limited from above. Then, several types of behavior of oscillatory charged shells are studied. In the presence of a horizon, it is shown that an oscillatory shell always enters the horizon and reemerges in a new asymptotically flat region of the extended Reissner–Nordström space–time. On the other hand, for an overcharged interior, i.e. a shell with no horizons, an example showing that the shell can achieve a stable equilibrium position is presented. The results presented have applications in brane scenarios with extra large dimensions, where the creation of tiny higher-dimensional charged black holes in current particle accelerators might be a real possibility, and generalize to higher dimensions previous calculations on the dynamics of charged shells in four dimensions.

STABILITYANALYSIS OF SCHWARZSCHILD-DAMOUR-SOLODUKHIN WORMHOLE

2021 ◽  
Vol 0 (1) ◽  
pp. 33-38
Author(s):  
G.F. AKHTARYANOVA ◽  
◽  
G.I. NIZAEVA ◽  
R.N. IZMAILOV ◽  
◽  
...  
Keyword(s):  
Black Hole ◽  
Thin Shell ◽  
Difficult Problem ◽  
Space Time ◽  
Regular Space ◽  
Schwarzschild Black Hole ◽  
Key Factor ◽  
Mass Constraint ◽  
Fixed Radius ◽  
External Forces

The equations of general relativity are nonlinear second-order partial differential equations, and, as a consequence, obtaining the exact solutions is a difficult problem. One of the solutions to this problem is to obtain models with a thin self-gravitating shell. This method is used to study most of the phenomena in the theory of gravity, where the reverse effect of matter on the geometry of space-time is a key factor. Another interesting problem that can be studied using the thin shell method is the «simulation» of a black hole. Consider a system consisting of a spherically symmetric Schwarzschild black hole and a thin shell surrounding it, located at a certain fixed distance from the black hole. From the viewpoint of gravitational physics, an observer at infinity is unable to distinguish a real black hole from a wormhole with a thin shell, in which the simulation condition is satisfied. Simulation of a black hole is possible only under sufficiently stringent conditions for the parameters of the model. In particular, the shell needs to be held at a fixed radius. In the general case, such a movement of the shell is non-geodesic, and external forces are required to hold it. The radius of the shell is also a parameter that determines the possibility / impossibility of simulation. In this paper, the radius is found for the case of a Schwarzschild black hole. In particular, the paper considers a model of a wormhole obtained as a result of gluing two space-times: a Schwarzschild black hole and a Damour-Solodukhin wormhole. The latter solution differs from the Schwarzschild black hole in the parameter of the dimensionless real deviation λ and is a twice asymptotically flat regular space-time. It is shown that they can be glued along a given radius. As a result, a thin shell is formed between two glued manifolds consisting of exotic matter. Cases are considered when the thin shell is stable. It turns out that zones corresponding to the «force» constraint are more restrictive than those corresponding to the «mass» constraint.

scholarly journals T-S-T Dual Black Hole

1997 ◽  
Vol 12 (12) ◽  
pp. 2293-2299
Author(s):  
Björn Andreas
Keyword(s):  
Black Hole ◽  
Space Time ◽  
Test String ◽  
White Hole ◽  
Duality Transformations ◽  
Black Hole Background

The sequence of intertwined T-S-T duality transformations acting on the 4D static uncharged black hole leads to a black hole background with horizon and singularity exchanged. It is shown that this space–time is extendible too. In particular we will see that a string moving into a black hole is dual to a string leaving a white hole. That offers the possibility that a test-string does not see the singularity.

scholarly journals Hawking evaporation cascade in the presence of backreaction effect

2017 ◽  
Vol 32 (16) ◽  
pp. 1750088 ◽  
Author(s):  
Avik Paul ◽  
Bibhas Ranjan Majhi
Keyword(s):  
Black Hole ◽  
Emission Spectrum ◽  
Event Horizon ◽  
Hawking Radiation ◽  
Space Time ◽  
Black Hole Mass ◽  
Planck Mass ◽  
Black Hole Background ◽  
Continuous Radiation ◽  
Physical Background

We study the cascade of Hawking emission spectrum from the event horizon in the presence of one loop backreaction effect in a black hole background. The space–time taken here is the modified Schwarzschild one. The analysis shows that it is possible to decrease the sparsity with the decrease in black hole mass. Moreover, at some particular value of mass, one has a continuous radiation cascade. This result is completely new and quite different from the usual one. An estimation of the mass for continuous one is also found. We see that the value is of the Planck mass order. In this process, it is observed that under a physical background, below a particular value of the mass, the Hawking radiation must stop and we have a remnant. This was absent in the earlier analysis.

scholarly journals LOGARITHMIC CORRECTION TO SCALING FOR MULTISPIN STRINGS IN THE AdS5 BLACK HOLE BACKGROUND

2008 ◽  
Vol 23 (05) ◽  
pp. 719-727
Author(s):  
A. L. LARSEN
Keyword(s):  
Black Hole ◽  
Radial Direction ◽  
Temperature Limit ◽  
Space Time ◽  
Explicit Solutions ◽  
Logarithmic Correction ◽  
High Temperature Limit ◽  
Black Hole Background ◽  
Correction To Scaling ◽  
The One

We find new explicit solutions describing closed strings spinning with equal angular momentum in two independent planes in the AdS5 black hole space–time. These are 2n-folded strings in the radial direction and also winding m times around an angular direction. We specially consider these solutions in the long string and high temperature limit, where it is shown that there is a logarithmic correction to the scaling between energy and spin. This is similar to the one-spin case. The strings are spinning, or actually orbiting around the black hole of the AdS5 black hole space–time, similar to the solutions previously found in black hole space–times.

Translocations In Space-Time and Simultaneous States of the Universe: Convergent Quantifications and Alternative Solutions from the Principles of Physics for the Challenges of “Time Travel” and “Parallel Universes”

2016 ◽  
pp. 4058-4069
Author(s):  
Michael A Persinger
Keyword(s):  
Single Photon ◽  
Rest Mass ◽  
Space Time ◽  
Hydrogen Line ◽  
Magnetic Forces ◽  
Universal Space ◽  
Potential Applications ◽  
Order Of Magnitude ◽  
Alternative Solutions ◽  
The Universe

                                Translation of four dimensional axes anywhere within the spatial and temporal boundaries of the universe would require quantitative values from convergence between parameters that reflect these limits. The presence of entanglement and volumetric velocities indicates that the initiating energy for displacement and transposition of axes would be within the upper limit of the rest mass of a single photon which is the same order of magnitude as a macroscopic Hamiltonian of the modified Schrödinger wave function. The representative metaphor is that any local 4-D geometry, rather than displaying restricted movement through Minkowskian space, would instead expand to the total universal space-time volume before re-converging into another location where it would be subject to cause-effect. Within this transient context the contributions from the anisotropic features of entropy and the laws of thermodynamics would be minimal.  The central operation of a fundamental unit of 10-20 J, the hydrogen line frequency, and the Bohr orbital time for ground state electrons would be required for the relocalized manifestation. Similar quantified convergence occurs for the ~1012 parallel states within space per Planck’s time which solve for phase-shift increments where Casimir and magnetic forces intersect.  Experimental support for these interpretations and potential applications is considered. The multiple, convergent solutions of basic universal quantities suggest that translations of spatial axes into adjacent spatial states and the transposition of four dimensional configurations any where and any time within the universe may be accessed but would require alternative perspectives and technologies.

scholarly journals Black hole S-matrix for a scalar field

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Panos Betzios ◽  
Nava Gaddam ◽  
Olga Papadoulaki
Keyword(s):  
Black Hole ◽  
Normal Modes ◽  
Massless Scalar ◽  
Scattering Process ◽  
Schwarzschild Black Hole ◽  
Asymptotically Flat ◽  
Scalar Particles ◽  
Black Hole Background ◽  
S Matrix ◽  
Do So

Abstract We describe a unitary scattering process, as observed from spatial infinity, of massless scalar particles on an asymptotically flat Schwarzschild black hole background. In order to do so, we split the problem in two different regimes governing the dynamics of the scattering process. The first describes the evolution of the modes in the region away from the horizon and can be analysed in terms of the effective Regge-Wheeler potential. In the near horizon region, where the Regge-Wheeler potential becomes insignificant, the WKB geometric optics approximation of Hawking’s is replaced by the near-horizon gravitational scattering matrix that captures non-perturbative soft graviton exchanges near the horizon. We perform an appropriate matching for the scattering solutions of these two dynamical problems and compute the resulting Bogoliubov relations, that combines both dynamics. This allows us to formulate an S-matrix for the scattering process that is manifestly unitary. We discuss the analogue of the (quasi)-normal modes in this setup and the emergence of gravitational echoes that follow an original burst of radiation as the excited black hole relaxes to equilibrium.

scholarly journals Normal-mode analysis for scalar fields in BTZ black-hole background

2009 ◽  
Vol 60 (2) ◽  
pp. 169-173 ◽  
Author(s):  
Sayan K. Chakrabarti ◽  
Pulak Ranjan Giri ◽  
Kumar S. Gupta
Keyword(s):  
Black Hole ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Scalar Fields ◽  
Mode Analysis ◽  
Btz Black Hole ◽  
Black Hole Background

scholarly journals TRAVERSABLE WORMHOLES IN A STRING CLOUD

2008 ◽  
Vol 17 (08) ◽  
pp. 1179-1196 ◽  
Author(s):  
MARTÍN G. RICHARTE ◽  
CLAUDIO SIMEONE
Keyword(s):  
Thin Shell ◽  
Dimensional Space ◽  
Space Time ◽  
Exotic Matter ◽  
Spherically Symmetric ◽  
Related Model ◽  
Traversable Wormholes ◽  
Dimensional Space Time ◽  
Thin Shell Wormholes ◽  
The Stability

We study spherically symmetric thin shell wormholes in a string cloud background in (3 + 1)-dimensional space–time. The amount of exotic matter required for the construction, the traversability and the stability of such wormholes under radial perturbations are analyzed as functions of the parameters of the model. In addition, in the appendices a nonperturbative approach to the dynamics and a possible extension of the analysis to a related model are briefly discussed.

Various types of holographic metal/superconductor phase transitions with dark matter sector

2016 ◽  
Vol 26 (06) ◽  
pp. 1750046
Author(s):  
Yan Peng ◽  
Tao Chen ◽  
Guohua Liu ◽  
Pengwei Ma
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Dark Matter ◽  
Phase Transitions ◽  
Transition Temperature ◽  
De Sitter ◽  
Holographic Superconductor ◽  
Black Hole Background ◽  
Critical Phase ◽  
Matter Sector

We generalize the holographic superconductor model with dark matter sector by including the Stückelberg mechanism in the four-dimensional anti-de Sitter (AdS) black hole background away from the probe limit. We study effects of the dark matter sector on the [Formula: see text]-wave scalar condensation and find that the dark matter sector affects the critical phase transition temperature and also the order of phase transitions. At last, we conclude that the dark matter sector brings richer physics in this general metal/superconductor system.

Sign in / Sign up

Export Citation Format

Share Document