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1.
Spherical gravitational collapse towards a black hole with non-zero tangential pressure is studied.Exact solutions corresponding to different equations of state are given.We find that when taking the tangential pressure into account,the exact solutions have three qualitatively different outcomes.For positive tangential pressure,the shell around a black hole may eventually collapse onto the black hole,or expand to infinity,or have a static but unstable solution,depending on the combination of black hole mass,mass of the shell and the pressure parameter.For vanishing or negative pressure,the shell will collapse onto the black hole.For all eventually collapsing solutions,the shell will cross the event horizon,instead of accumulating outside theeventhorizon,even if clocked by a distant stationary observer. 相似文献
2.
In this paper,a canonical ensemble model for black hole quantum tunneling radiation is introduced.We find that the probability distribution function is the same as the emission rate of a spherical shell in the Parikh-Wilczek tunneling framework.With this model,the probability distribution function corresponding to the emission shell system is calculated.Therefore,the concrete quantum tunneling spectrum of the Schwarzschild black hole is obtained. 相似文献
3.
R. Siegl 《General Relativity and Gravitation》2011,43(1):155-161
This paper explores a thin shell of ideal fluid surrounding a Kerr black hole assuming a slow rotation and retaining only
first order terms of expansion in angular momentum. It is shown that a physically feasible shell rotates rigidly in this approximation
and that the interior black hole mass is constrained by other parameters of the system. Furthermore, it is shown that the
local inertial frames are “dragged” by the shell as the shell radius approaches the gravitational radius, which is similar
to results of studies considering a flat interior. 相似文献
4.
A canonical ensemble model for a R-N black hole quantum tunneling radiation is introduced in this paper. We discover that the probability distribution function is equal to the emission rate of a spherical shell in the Parikh-Wilczek tunneling framework. Taking the generalized uncertainty principle into account, the probability distribution function corresponding to the emission shell system can be calculated with this model. As a result the concrete quantum tunneling spectrum for a R-N black hole is obtained. 相似文献
5.
The gravitational collapse of a star is an important issue both for general relativity and astrophysics, which is related to the well-known “frozen star” paradox. This paradox has been discussed intensively and seems to have been solved in the comoving-like coordinates. However, to a real astrophysical observer within a finite time, this problem should be discussed in the point of view of the distant rest-observer, which is the main purpose of this Letter. Following the seminal work of Oppenheimer and Snyder (1939), we present the exact solution for one or two dust shells collapsing towards a pre-existing black hole. We find that the metric of the inner region of the shell is time-dependent and the clock inside the shell becomes slower as the shell collapses towards the pre-existing black hole. This means the inner region of the shell is influenced by the property of the shell, which is contrary to the result in Newtonian theory. It does not contradict the Birkhoff's theorem, since in our case we cannot arbitrarily select the clock inside the shell in order to ensure the continuity of the metric. This result in principle may be tested experimentally if a beam of light travels across the shell, which will take a longer time than without the shell. It can be considered as the generalized Shapiro effect, because this effect is due to the mass outside, but not inside as the case of the standard Shapiro effect. We also found that in real astrophysical settings matter can indeed cross a black hole's horizon according to the clock of an external observer and will not accumulate around the event horizon of a black hole, i.e., no “frozen star” is formed for an external observer as matter falls towards a black hole. Therefore, we predict that only gravitational wave radiation can be produced in the final stage of the merging process of two coalescing black holes. Our results also indicate that for the clock of an external observer, matter, after crossing the event horizon, will never arrive at the “singularity” (i.e. the exact center of the black hole), i.e., for all black holes with finite lifetimes their masses are distributed within their event horizons, rather than concentrated at their centers. We also present a worked-out example of the Hawking's area theorem. 相似文献
6.
The dynamics of a thin spherically symmetric gravitating shell around an electrically charged Reissner—Nordström black hole is considered. The energy—momentum tensor of an electrically neutral shell is modeled by an ideal fluid with a polytropic equation of state. The dynamics of a shell with a dust equation of state can be traced completely analytically. The Carter—Penrose diagrams that describe the global geometry and all possible types of motions of a gravitating shell in the case of an eternal black hole have been constructed.The conditions have been found under which stable oscillatory motions of the shell take place. These transfer it successively from one universe to the next in an infinite series of identical universes. Such stable oscillatory shell motions are shown to be possible for an arbitrary polytropic equation of state of the shell. 相似文献
7.
In this paper, we examine the effect of dark matter to a Kerr black hole of mass m. The metric is derived using the Newman-Janis algorithm, where the seed metric originates from the Schwarzschild black hole surrounded by a spherical shell of dark matter with mass M and thickness Δrs. The seed metric is also described in terms of a piecewise mass function with three different conditions. Specializing in the non-trivial case where the observer resides inside the dark matter shell, we analyzed how the effective mass of the black hole environment affects the basic black hole properties. A high concentration of dark matter near the rotating black hole is needed to have considerable deviations on the horizons, ergosphere, and photonsphere radius. The time-like geodesic, however, shows more sensitivity to deviation even at very low dark matter density. Further, the location of energy extraction via the Penrose process is also shown to remain unchanged. With how the dark matter distribution is described in the mass function, and the complexity of how the shadow radius is defined for a Kerr black hole, deriving an analytic expression for Δrs as a condition for notable dark matter effects to occur remains inconvenient. 相似文献
8.
William A Hiscock 《Annals of Physics》1981,131(2):245-268
The possibility of converting a Reissner-Nordström black hole into a naked singularity by means of test particle accretion is considered. The dually charged Reissner-Nordström metric describes a black hole only when M2 > Q3 + P2. The test particle equations of motion are shown to allow test particles with arbitrarily large magnetic charge/mass ratios to fall radially into electrically charged black holes. To determine the nature of the final state (black hole or naked singularity) an exact solution of Einstein's equations representing a spherical shell of magnetically charged dust falling into an electrically charged black hole is studied. Naked singularities are never formed so long as the weak energy condition is obeyed by the infalling matter. The differences between the spherical shell model and an infalling point test particle are examined and discussed. 相似文献
9.
It is shown that the effect of particle creation by a black hole is a consequence of the Casimir effect for a spherical shell. The temperature of black-body radiation coincides with that obtained by Hawking. 相似文献
10.
11.
《Nuclear Physics B》2001,603(3):555-577
The dynamics of a thin spherically symmetric shell of zero-rest-mass matter in its own gravitational field is studied. A form of action principle is used that enables the reformulation of the dynamics as motion on a fixed background manifold. A self-adjoint extension of the Hamiltonian is obtained via the group quantization method. Operators of position and of direction of motion are constructed. The shell is shown to avoid the singularity, to bounce and to re-expand to that asymptotic region from which it contracted; the dynamics is, therefore, truly unitary. If a wave packet is sufficiently narrow and/or energetic then an essential part of it can be concentrated under its Schwarzschild radius near the bounce point but no black hole forms. The quantum Schwarzschild horizon is a linear combination of a black and white hole apparent horizons rather than an event horizon. 相似文献
12.
The Parikh–Wilczek tunnelling framework, which treats Hawking radiation as a tunnelling process, is investigated once more in this work. The first order correction, the log-corrected entropy-area relation, emerges naturally in the tunnelling picture if we consider the emission of a spherical shell. The second order correction to the emission rate for the Schwarzschild black hole is also calculated. At this level, the entropy of the black hole will contain three parts: the usual Bekenstein–Hawking entropy, a logarithmic term and an inverse area term. We find that the coefficient of the logarithmic term is −1. Thus, apart from a coefficient, our correction to the black hole entropy is consistent with that calculated in loop quantum gravity. 相似文献
13.
We consider boson stars and black holes in scalar electrodynamics with a V-shaped scalar potential. The boson stars come in two types, having either ball-like or shell-like charge density. We analyze the properties of these solutions and determine their domains of existence. When mass and charge become equal, the space–times develop a throat. The shell-like solutions need not be globally regular, but may possess a horizon. The space–times then consist of a Schwarzschild-type black hole in the interior, surrounded by a shell of charged matter, and thus a Reissner–Nordström-type space–time in the exterior. These solutions violate black hole uniqueness. The mass of the black hole solutions is related to the mass of the regular shell-like solutions by a mass formula of the type first obtained within the isolated horizon framework. 相似文献
14.
The collapse of a spherically symmetric charged thin shell in a Reissner-Nordstrøm field can lead to an extreme black hole. No contradiction to the assumption of Cosmic Censorship results. 相似文献
15.
We have calculated a discrete spectrum and found an exact analytical solution in the form of Meixner polynomials for the wavefunction of a thin gravitating shell in the Reissner-Nordström geometry. We show that there is no extreme state in the quantum spectrum of the gravitating shell, as in the case of an extreme black hole. 相似文献
16.
F. Rahaman M. Kalam K. A. Rahman S. Chakraborti 《General Relativity and Gravitation》2007,39(7):945-956
Recently, Dadhich et al. (Phys. Lett. B 487, 1, 2000) have discovered a black hole solution localized on a three brane in five dimensional gravity in the Randall–Sundrum
scenario. In this article, we develop a new class of thin shell wormhole by surgically grafting above two black hole spacetimes.
Various aspects of this thin wormhole are also analyzed. 相似文献
17.
Karel V. Kuchar 《International Journal of Theoretical Physics》1999,38(4):1033-1049
Gravitating shells lead to simple minisuperspacemodels of black hole formation by gravitational collapseof matter. I interpret here the Hajicek–Kijowskivariational principle for spacetime with a shell as a Dirac–ADM action principle along atimelike foliation including the shell as a leaf. Byreducing this action by spherical symmetry, I obtain theHamiltonian constraint of a collapsing dust shell and use it as a prelude to canonicalquantization. 相似文献
18.
S. V. Chernov 《Journal of Experimental and Theoretical Physics》2013,117(5):827-832
The geometrodynamics of a thin, dust, electrically neutral shell in the metric of a charged Reissner-Nordström black hole is considered. The Arnowitt-Deser-Misner formalism is used to construct the thin-shell Hamiltonian. The wave equation is derived. The wave equation is shown to be a second-order homogeneous difference equation. Exact analytical solutions have been found. 相似文献
19.
20.
F. Rahaman K. A. Rahman S. A. Rakib Peter K. F. Kuhfittig 《International Journal of Theoretical Physics》2010,49(10):2364-2378
We investigate a new thin-shell wormhole constructed by surgically grafting two regular charged black holes arising from the
action using nonlinear electrodynamics coupled to general relativity. The stress-energy components within the shell violate
the null and weak energy conditions but obey the strong energy condition. Several other aspects of this thin-shell wormhole
are also analyzed. The most important finding is that the presence of a charge is essential for producing a thin-shell wormhole
that is stable to linearized spherically symmetric perturbations about a static equilibrium solution. The precise conditions
depend on various properties of the black hole. 相似文献