113 research outputs found
Uniqueness of the asymptotic AdS3 geometry
We explicitly show that in (2+1) dimensions the general solution of the
Einstein equations with negative cosmological constant on a neigbourhood of
timelike spatial infinity can be obtained from BTZ metrics by coordinate
transformations corresponding geometrically to deformations of their spatial
infinity surface. Thus, whatever the topology and geometry of the bulk, the
metric on the timelike extremities is BTZ.Comment: LaTeX, 8 pages, no figures, version that will appear in Class. Quant.
Gra
Towards black hole scattering
We study black holes in three-dimensional Chern-Simons gravity with a
negative cosmological constant. In particular, we identify how the Chern-Simons
interactions between a scattering particle and a black hole project the
particle wavefunction onto a wavefunction in the black hole background. We also
analyze the set of space-times that should be allowed in the theory and the way
in which boundary conditions affect the spectrum of space-times.Comment: 12 pages, v2: reference added, typos correcte
Supergeometry of Three Dimensional Black Holes
We show how the supersymmetric properties of three dimensional black holes
can be obtained algebraically. The black hole solutions are constructed as
quotients of the supergroup by a discrete subgroup of its
isometry supergroup. The generators of the action of the isometry supergroup
which commute with these identifications are found. These yield the
supersymmetries for the black hole as found in recent studies as well as the
usual geometric isometries. It is also shown that in the limit of vanishing
cosmological constant, the black hole vacuum becomes a null orbifold, a
solution previously discussed in the context of string theory.Comment: 12 pages, harvmac, discussion of rotating black hole added, some
minor corrections, reference adde
Spherically Symmetric Gravity as a Completely Integrable System
It is shown - in Ashtekar's canonical framework of General Relativity - that
spherically symmetric (Schwarzschild) gravity in 4 dimensional space-time
constitutes a finite dimensional completely integrable system. Canonically
conjugate observables for asymptotically flat space-times are masses as action
variables and - surprisingly - time variables as angle variables, each of which
is associated with an asymptotic "end" of the Cauchy surfaces. The emergence of
the time observable is a consequence of the Hamiltonian formulation and its
subtleties concerning the slicing of space and time and is not in contradiction
to Birkhoff's theorem. The results are of interest as to the concept of time in
General Relativity. They can be formulated within the ADM formalism, too.
Quantization of the system and the associated Schr\"odinger equation depend on
the allowed spectrum of the masses.Comment: 20.p., Latex, PITHA 93-3
Phase behaviour of additive binary mixtures in the limit of infinite asymmetry
We provide an exact mapping between the density functional of a binary
mixture and that of the effective one-component fluid in the limit of infinite
asymmetry. The fluid of parallel hard cubes is thus mapped onto that of
parallel adhesive hard cubes. Its phase behaviour reveals that demixing of a
very asymmetric mixture can only occur between a solvent-rich fluid and a
permeated large particle solid or between two large particle solids with
different packing fractions. Comparing with hard spheres mixtures we conclude
that the phase behaviour of very asymmetric hard-particle mixtures can be
determined from that of the large component interacting via an adhesive-like
potential.Comment: Full rewriting of the paper (also new title). 4 pages, LaTeX, uses
revtex, multicol, epsfig, and amstex style files, to appear in Phys. Rev. E
(Rapid Comm.
Multi-Black-Holes in Three Dimensions
We construct time-dependent multi-centre solutions to three-dimensional
general relativity with zero or negative cosmological constant. These solutions
correspond to dynamical systems of freely falling black holes and conical
singularities, with a multiply connected spacetime topology. Stationary
multi-black-hole solutions are possible only in the extreme black hole case.Comment: 8 pages, \LaTex, 4 figures (available on request), GCR 94/02/0
Scalar field dynamics in warped AdS_3 black hole background
We study the normal modes of a scalar field in the background of a warped
AdS_3 black hole which arises in topologically massive gravity. We discuss the
normal mode spectrum using the brick wall boundary condition. In addition, we
investigate the possibility of a more general boundary condition for the scalar
field.Comment: 7 pages, one figure, revtex4, refs. added and minor modifications in
tex
Automorphisms of Real 4 Dimensional Lie Algebras and the Invariant Characterization of Homogeneous 4-Spaces
The automorphisms of all 4-dimensional, real Lie Algebras are presented in a
comprehensive way. Their action on the space of , real, symmetric
and positive definite, matrices, defines equivalence classes which are used for
the invariant characterization of the 4-dimensional homogeneous spaces which
possess an invariant basis.Comment: LaTeX2e, 23 pages, 2 Tables. To appear in Journal of Physics A:
Mathematical & Genera
Asymptotic symmetries in 3d gravity with torsion
We study the nature of asymptotic symmetries in topological 3d gravity with
torsion. After introducing the concept of asymptotically anti-de Sitter
configuration, we find that the canonical realization of the asymptotic
symmetry is characterized by the Virasoro algebra with classical central
charge, the value of which is the same as in general relativity: c=3l/2G.Comment: 25 pages, RevTeX, no figure
More on Superstrings in AdS(3) x N
We study superstring theories on AdS(3) x N backgrounds yielding N=2,3,4
extended superconformal symmetries in the dual boundary CFT. In each case the
necessary constraints on the internal worldsheet theory N are found.Comment: JHEP style, 22 pages; v2: new references and a couple of sentences on
N=1 are adde
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