1,005 research outputs found
A theory of thin shells with orbiting constituents
The self-gravitating, spherically symmetric thin shells built of orbiting
particles are sstudied. Two new features are found. One is the minimal possible
value for an angular momentum of particles, above which elleptic orbits become
possible. The second is the coexistence of both the wormhole solutions and the
elleptic or hyperbolic orbits for the same values of the parameters (but
different initial conditions). Possible applications of these results to
astrophysics and quantum black holes are briefly discussed.Comment: 22 pages, Latex, 10 eps figures. CERN preprint no. CERN-TH 2000-16
Hidden supersymmetry and Berezin quantization of N=2, D=3 spinning superparticles
The first quantized theory of N=2, D=3 massive superparticles with arbitrary
fixed central charge and (half)integer or fractional superspin is constructed.
The quantum states are realized on the fields carrying a finite dimensional, or
a unitary infinite dimensional representation of the supergroups OSp(2|2) or
SU(1,1|2). The construction originates from quantization of a classical model
of the superparticle we suggest. The physical phase space of the classical
superparticle is embedded in a symplectic superspace
, where the inner K\"ahler supermanifold
provides
the particle with superspin degrees of freedom. We find the relationship
between Hamiltonian generators of the global Poincar\'e supersymmetry and the
``internal'' SU(1,1|2) one. Quantization of the superparticle combines the
Berezin quantization on and the conventional Dirac quantization
with respect to space-time degrees of freedom. Surprisingly, to retain the
supersymmetry, quantum corrections are required for the classical N=2
supercharges as compared to the conventional Berezin method. These corrections
are derived and the Berezin correspondence principle for underlying
their origin is verified. The model admits a smooth contraction to the N=1
supersymmetry in the BPS limit.Comment: 43 pages, LaTeX Version 2.0
Dynamics of a thin shell in the Reissner-Nordstrom metric
We describe the dynamics of a thin spherically symmetric gravitating shell in
the Reissner-Nordstrom metric of the electrically charged black hole. The
energy-momentum tensor of electrically neutral shell is modelled by the perfect
fluid with a polytropic equation of state. The motion of a shell is described
fully analytically in the particular case of the dust equation of state. We
construct the Carter-Penrose diagrams for the global geometry of the eternal
black hole, which illustrate all possible types of solutions for moving shell.
It is shown that for some specific range of initial parameters there are
possible the stable oscillating motion of the shell transferring it
consecutively in infinite series of internal universes. We demonstrate also
that this oscillating type of motion is possible for an arbitrary polytropic
equation of state on the shell.Comment: 17 pages, 7 figure
Vacuum decay via Lorentzian wormholes
We speculate about the spacetime description due to the presence of
Lorentzian wormholes (handles in spacetime joining two distant regions or other
universes) in quantum gravity. The semiclassical rate of production of these
Lorentzian wormholes in Reissner-Nordstr\"om spacetimes is calculated as a
result of the spontaneous decay of vacuum due to a real tunneling
configuration. In the magnetic case it only depends on the field theoretical
fine structure constant. We predict that the quantum probability corresponding
to the nucleation of such geodesically complete spacetimes should be actually
negligible in our physical Universe
Vacuum shell in the Schwarzschild-de Sitter world
We construct the classification scheme for all possible evolution scenarios
and find the corresponding global geometries for dynamics of a thin spherical
vacuum shell in the Schwarzschild-de Sitter metric. This configuration is
suitable for the modelling of vacuum bubbles arising during cosmological phase
transitions in the early Universe. The distinctive final types of evolution
from the local point of view of a rather distant observer are either the
unlimited expansion of the shell or its contraction with a formation of black
hole (with a central singularity) or wormhole (with a baby universe in
interior).Comment: 15 pages, 8 figure
A Generalization of the Bargmann-Fock Representation to Supersymmetry by Holomorphic Differential Geometry
In the Bargmann-Fock representation the coordinates act as bosonic
creation operators while the partial derivatives act as
annihilation operators on holomorphic -forms as states of a -dimensional
bosonic oscillator. Considering also -forms and further geometrical objects
as the exterior derivative and Lie derivatives on a holomorphic , we
end up with an analogous representation for the -dimensional supersymmetric
oscillator. In particular, the supersymmetry multiplet structure of the Hilbert
space corresponds to the cohomology of the exterior derivative. In addition, a
1-complex parameter group emerges naturally and contains both time evolution
and a homotopy related to cohomology. Emphasis is on calculus.Comment: 11 pages, LaTe
Felix Alexandrovich Berezin and his work
This is a survey of Berezin's work focused on three topics: representation
theory, general concept of quantization, and supermathematics.Comment: LaTeX, 27 page
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