54 research outputs found
Aspects of (2+1) dimensional gravity: AdS3 asymptotic dynamics in the framework of Fefferman-Graham-Lee theorems
Using the Chern-Simon formulation of (2+1) gravity, we derive, for the
general asymptotic metrics given by the Fefferman-Graham-Lee theorems, the
emergence of the Liouville mode associated to the boundary degrees of freedom
of (2+1) dimensional anti de Sitter geometries.Comment: 6 pages, Latex, presented at the Journees Relativistes 99, Weimar,
September 12-17, 1999; revised version with minor modifications and 1
reference adde
Global geometry of the 2+1 rotating black hole
The generic rotating BTZ black hole, obtained by identifications in AdS3
space through a discrete subgroup of its isometry group, is investigated within
a Lie theoretical context. This space is found to admit a foliation by
two-dimensional leaves, orbits of a two-parameter subgroup of SL(2,R) and
invariant under the BTZ identification subgroup. A global expression for the
metric is derived, allowing a better understanding of the causal structure of
the black hole.Comment: 9 pages, 1 figur
Einstein-Podolsky-Rosen correlations between two uniformly accelerated oscillators
We consider the quantum correlations, i.e. the entanglement, between two
systems uniformly accelerated with identical acceleration a in opposite Rindler
quadrants which have reached thermal equilibrium with the Unruh heat bath. To
this end we study an exactly soluble model consisting of two oscillators
coupled to a massless scalar field in 1+1 dimensions. We find that for some
values of the parameters the oscillators get entangled shortly after the moment
of closest approach. Because of boost invariance there are an infinite set of
pairs of positions where the oscillators are entangled. The maximal
entanglement between the oscillators is found to be approximately 1.4
entanglement bits.Comment: 11 page
Massive spin 2 propagator on de Sitter space
We compute the Pauli-Jordan, Hadamard and Feynman propagators for the massive
metrical perturbations on de Sitter space. They are expressed both in terms of
mode sums and in invariant forms.Comment: 30 pages + 1 eps fi
G3-homogeneous gravitational instantons
We provide an exhaustive classification of self-dual four-dimensional
gravitational instantons foliated with three-dimensional homogeneous spaces,
i.e. homogeneous self-dual metrics on four-dimensional Euclidean spaces
admitting a Bianchi simply transitive isometry group. The classification
pattern is based on the algebra homomorphisms relating the Bianchi group and
the duality group SO(3). New and general solutions are found for Bianchi III.Comment: 24 pages, few correction
Quantum charged fields in Rindler space
We study, using Rindler coordinates, the quantization of a charged scalar
field interacting with a constant, external, electric field. First we establish
the expression of the Schwinger vacuum decay rate, using the operator
formalism. Then we rederive it in the framework of the Feynman path integral
method. Our analysis reinforces the conjecture which identifies the zero
winding sector of the Minkowski propagator with the Rindler propagator.
Moreover we compute the expression of the Unruh's modes that allow to make
connection between Minkowskian and Rindlerian quantization scheme by purely
algebraic relations. We use these modes to study the physics of a charged two
level detector moving in an electric field whose transitions are due to the
exchange of charged quanta. In the limit where the Schwinger pair production
mechanism of the exchanged quanta becomes negligible we recover the Boltzman
equilibrium ratio for the population of the levels of the detector. Finally we
explicitly show how the detector can be taken as the large mass and charge
limit of an interacting fields system.Comment: 1 Tex file + 5 eps figure
Quantum Einstein-Dirac Bianchi Universes
We study the mini--superspace quantization of spatially homogeneous (Bianchi)
cosmological universes sourced by a Dirac spinor field. The quantization of the
homogeneous spinor leads to a finite-dimensional fermionic Hilbert space and
thereby to a multi-component Wheeler-DeWitt equation whose main features are:
(i) the presence of spin-dependent Morse-type potentials, and (ii) the
appearance of a q-number squared-mass term, which is of order , and which is affected by ordering ambiguities. We give the exact
quantum solution of the Bianchi type-II system (which contains both scattering
states and bound states), and discuss the main qualitative features of the
quantum dynamics of the (classically chaotic) Bianchi type-IX system. We
compare the exact quantum dynamics of fermionic cosmological billiards to
previous works that described the spinor field as being either classical or
Grassmann-valued.Comment: 50 page
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