4,456 research outputs found
Statistical Mechanics of Charged Black Holes in Induced Einstein-Maxwell Gravity
The statistical origin of the entropy of charged black holes in models of
induced Einstein-Maxwell gravity is investigated. The constituents inducing the
Einstein-Maxwell action are charged and interact with an external gauge
potential. This new feature, however, does not change divergences of the
statistical-mechanical entropy of the constituents near the horizon. It is
demonstrated that the mechanism of generation of the Bekenstein-Hawking entropy
in induced gravity is universal and it is basically the same for charged and
neutral black holes. The concrete computations are carried out for induced
Einstein-Maxwell gravity with a negative cosmological constant in three
space-time dimensions.Comment: 16 pages, latex, no figure
Quantum Entanglement and Teleportation in Higher Dimensional Black Hole Spacetimes
We study the properties of quantum entanglement and teleportation in the
background of stationary and rotating curved space-times with extra dimensions.
We show that a maximally entangled Bell state in an inertial frame becomes less
entangled in curved space due to the well-known Hawking-Unruh effect. The
degree of entanglement is found to be degraded with increasing the extra
dimensions. For a finite black hole surface gravity, the observer may choose
higher frequency mode to keep high level entanglement. The fidelity of quantum
teleporation is also reduced because of the Hawking-Unruh effect. We discuss
the fidelity as a function of extra dimensions, mode frequency, black hole mass
and black hole angular momentum parameter for both bosonic and fermionic
resources.Comment: 15 pages, 10 figures,contents expande
Covariant Calculation of General Relativistic Effects in an Orbiting Gyroscope Experiment
We carry out a covariant calculation of the measurable relativistic effects
in an orbiting gyroscope experiment. The experiment, currently known as Gravity
Probe B, compares the spin directions of an array of spinning gyroscopes with
the optical axis of a telescope, all housed in a spacecraft that rolls about
the optical axis. The spacecraft is steered so that the telescope always points
toward a known guide star. We calculate the variation in the spin directions
relative to readout loops rigidly fixed in the spacecraft, and express the
variations in terms of quantities that can be measured, to sufficient accuracy,
using an Earth-centered coordinate system. The measurable effects include the
aberration of starlight, the geodetic precession caused by space curvature, the
frame-dragging effect caused by the rotation of the Earth and the deflection of
light by the Sun.Comment: 7 pages, 1 figure, to be submitted to Phys. Rev.
Self-diffusion in binary blends of cyclic and linear polymers
A lattice model is used to estimate the self-diffusivity of entangled cyclic
and linear polymers in blends of varying compositions. To interpret simulation
results, we suggest a minimal model based on the physical idea that constraints
imposed on a cyclic polymer by infiltrating linear chains have to be released,
before it can diffuse beyond a radius of gyration. Both, the simulation, and
recently reported experimental data on entangled DNA solutions support the
simple model over a wide range of blend compositions, concentrations, and
molecular weights.Comment: 10 pages, 2 figure
Black Hole Pair Creation and the Entropy Factor
It is shown that in the instanton approximation the rate of creation of black
holes is always enhanced by a factor of the exponential of the black hole
entropy relative to the rate of creation of compact matter distributions
(stars). This result holds for any generally covariant theory of gravitational
and matter fields that can be expressed in Hamiltonian form. It generalizes the
result obtained previously for the pair creation of magnetically charged black
holes by a magnetic field in Einstein--Maxwell theory. The particular example
of pair creation of electrically charged black holes by an electric field in
Einstein--Maxwell theory is discussed in detail.Comment: (12 pages, ReVTeX) Revised version of "Pair Creation of Electrically
Charged Black Holes". New section shows that the BH pair creation rate is
enhanced by a factor for any Hamiltonian gravity + matter
theor
Energy, Hamiltonian, Noether Charge, and Black Holes
It is shown that in general the energy and the Hamiltonian of matter fields on the black hole exterior play different roles. is a generator of the time evolution along the Killing time while enters the first law of black hole thermodynamics. For non-minimally
coupled fields the difference is not zero and is a Noether
charge analogous to that introduced by Wald to define the black hole
entropy. If fields vanish at the spatial boundary, is reduced to an
integral over the horizon. The analysis is carried out and an explicit
expression for is found for general diffeomorphism invariant theories. As
an extension of the results by Wald et al, the first law of black hole
thermodynamics is derived for arbitrary weak matter fields.Comment: 20 pages, latex, no figure
Late-time evolution of nonlinear gravitational collapse
We study numerically the fully nonlinear gravitational collapse of a
self-gravitating, minimally-coupled, massless scalar field in spherical
symmetry. Our numerical code is based on double-null coordinates and on free
evolution of the metric functions: The evolution equations are integrated
numerically, whereas the constraint equations are only monitored. The numerical
code is stable (unlike recent claims) and second-order accurate. We use this
code to study the late-time asymptotic behavior at fixed (outside the black
hole), along the event horizon, and along future null infinity. In all three
asymptotic regions we find that, after the decay of the quasi-normal modes, the
perturbations are dominated by inverse power-law tails. The corresponding power
indices agree with the integer values predicted by linearized theory. We also
study the case of a charged black hole nonlinearly perturbed by a (neutral)
self-gravitating scalar field, and find the same type of behavior---i.e.,
quasi-normal modes followed by inverse power-law tails, with the same indices
as in the uncharged case.Comment: 14 pages, standard LaTeX, 18 Encapsulated PostScript figures. A new
convergence test and a determination of QN ringing were added, in addition to
correction of typos and update of reference
Perturbative stability of the QCD analysis of DIS data
We perform pQCD analysis of the existing DIS data for charged leptons with
account of corrections up to the NNLO. The parton distributions, value of
strong coupling constant, and high-twist terms are extracted and their
stability with respect to account of the NNLO corrections is analyzed. All the
quantities are generally stable within their experimental errors. Obtained
value of the strong coupling constant is with a guess .Comment: 4 pages, LATEX, 3 figures (EPS). Talk presented at the 37th
Rencontres de Moriond, QCD and Hadronic Interactions, Les Arcs 1800 (France),
March 16-23 200
Entropies of Rotating Charged Black Holes from Conformal Field Theory at Killing Horizons
The covariant phase technique is used to compute the constraint algebra of
the stationary axisymmetric charged black hole. A standard Virasoro subalgebra
with corresponding central charge is constructed at a Killing horizon with
Carlip's boundary conditions. For the Kerr-Newman black hole and the
Kerr-Newman-AdS black hole, the density of states determined by conformal
fields theory methods yields the statistical entropy which agrees with the
Bekenstein-Hawking entropy.Comment: 12 pages, no figure, RevTe
On naked singularities in higher dimensional Vaidya space-times
We investigate the end state of gravitational collapse of null fluid in
higher dimensional space-times. Both naked singularities and black holes are
shown to be developing as final outcome of the collapse. The naked singularity
spectrum in collapsing Vaidya region (4D) gets covered with increase in
dimensions and hence higher dimensions favor black hole in comparison to naked
singularity. The Cosmic Censorship Conjecture will be fully respected for a
space of infinite dimension.Comment: 9 pages, LateX, Minor changes. Accepted in Phys. Rev.
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