4,105 research outputs found
Stability and hyperfine structure of the four- and five-body muon-atomic clusters and
Based on the results of accurate variational calculations we demonstrate
stability of the five-body negatively charged ions . Each of these five-body ions contains two electrons , one
negatively charged muon and two nuclei of the hydrogen isotopes . The bound state properties of these five-body ions, including
their hyperfine structure, are briefly discussed. We also investigate the
hyperfine structure of the ground states of the four-body muonic quasi-atoms
. In particular, we determine the hyperfine
structure splittings for the ground state of the four-body muonic quasi-atoms:
and
Energy flux through the horizon in the black hole-domain wall systems
We study various configurations in which a domain wall (or cosmic string),
described by the Nambu-Goto action, is embedded in a background space-time of a
black hole in and higher dimensional models. We calculate energy fluxes
through the black hole horizon. In the simplest case, when a static domain wall
enters the horizon of a static black hole perperdicularly, the energy flux is
zero. In more complicated situations, where parameters which describe the
domain wall surface are time and position dependent, the flux is non-vanishing
is principle. These results are of importance in various conventional
cosmological models which accommodate the existence of domain walls and strings
and also in brane world scenarios.Comment: references added, accepted for publication in JHE
Thermonuclear burn-up in deuterated methane
The thermonuclear burn-up of highly compressed deuterated methane CD is
considered in the spherical geometry. The minimal required values of the
burn-up parameter are determined for various
temperatures and densities . It is shown that thermonuclear burn-up
in becomes possible in practice if its initial density exceeds
. Burn-up in CDT methane
requires significantly ( 100 times) lower compressions. The developed
approach can be used in order to compute the critical burn-up parameters in an
arbitrary deuterium containing fuel
Thorny Spheres and Black Holes with Strings
We consider thorny spheres, that is 2-dimensional compact surfaces which are
everywhere locally isometric to a round sphere except for a finite number
of isolated points where they have conical singularities. We use thorny spheres
to generate, from a spherically symmetric solution of the Einstein equations,
new solutions which describe spacetimes pierced by an arbitrary number of
infinitely thin cosmic strings radially directed. Each string produces an angle
deficit proportional to its tension, while the metric outside the strings is a
locally spherically symmetric solution. We prove that there can be arbitrary
configurations of strings provided that the directions of the strings obey a
certain equilibrium condition. In general this equilibrium condition can be
written as a force-balance equation for string forces defined in a flat 3-space
in which the thorny sphere is isometrically embedded, or as a constraint on the
product of holonomies around strings in an alternative 3-space that is flat
except for the strings. In the case of small string tensions, the constraint
equation has the form of a linear relation between unit vectors directed along
the string axes.Comment: 37 pages, 11 figure
On the bound state of the antiproton-deuterium-tritium ion
The properties of the weakly-bound state in the ion
are investigated with the use of the results of highly accurate computations.
The hyperfine structure splitting of this ion is investigated. We also evaluate
the life-time of the ion against the nuclear fusion and
discuss a possibility to evaluate the corresponding annihilation rate(s)
Interaction of a brane with a moving bulk black hole
We study the interaction of an n-dimensional topological defect (n-brane)
described by the Nambu-Goto action with a higher-dimensional Schwarzschild
black hole moving in the bulk spacetime. We derive the general form of the
perturbation equations for an n-brane in the weak field approximation and solve
them analytically in the most interesting cases. We specially analyze
applications to brane world models. We calculate the induced geometry on the
brane generated by a moving black hole. From the point of view of a brane
observer, this geometry can be obtained by solving (n+1)-dimensional Einstein's
equations with a non-vanishing right hand side. We calculate the effective
stress-energy tensor corresponding to this `shadow-matter'. We explicitly show
that there exist regions on the brane where a brane observer sees an apparent
violation of energy conditions. We also study the deflection of light
propagating in the region of influence of this `shadow matter'.Comment: version accepted for publication in Phys. Rev.
Bound state spectra of three-body muonic molecular ions
The results of highly accurate calculations are presented for all twenty-two
known bound and states in the six
three-body muonic molecular ions and
. A number of bound state properties of these muonic molecular ions have
been determined numerically to high accuracy. The dependence of the total
energies of these muonic molecules upon particle masses is considered. We also
discuss the current status of muon-catalysis of nuclear fusion reactions.Comment: This is the final version. All `techical' troubles with the
Latex-file have been resolved. A few misprints/mistakes in the text were
correcte
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
Gauge field theory for Poincar\'{e}-Weyl group
On the basis of the general principles of a gauge field theory the gauge
theory for the Poincar\'{e}-Weyl group is constructed. It is shown that tetrads
are not true gauge fields, but represent functions from true gauge fields:
Lorentzian, translational and dilatational ones. The equations of gauge fields
which sources are an energy-momentum tensor, orbital and spin momemta, and also
a dilatational current of an external field are obtained. A new direct
interaction of the Lorentzian gauge field with the orbital momentum of an
external field appears, which describes some new effects. Geometrical
interpretation of the theory is developed and it is shown that as a result of
localization of the Poincar\'{e}-Weyl group spacetime becomes a Weyl-Cartan
space. Also the geometrical interpretation of a dilaton field as a component of
the metric tensor of a tangent space in Weyl-Cartan geometry is proposed.Comment: LaTex, 27 pages, no figure
Continuous Self-Similarity Breaking in Critical Collapse
This paper studies near-critical evolution of the spherically symmetric
scalar field configurations close to the continuously self-similar solution.
Using analytic perturbative methods, it is shown that a generic growing
perturbation departs from the critical Roberts solution in a universal way. We
argue that in the course of its evolution, initial continuous self-similarity
of the background is broken into discrete self-similarity with echoing period
, reproducing the symmetries of the critical
Choptuik solution.Comment: RevTeX 3.1, 28 pages, 5 figures; discussion rewritten to clarify
several issue
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