94 research outputs found
Non-asymptotically flat, non-dS/AdS dyonic black holes in dilaton gravity
We present exact spherically symmetric dyonic black hole solutions in
four-dimensional Einstein-Maxwell-dilaton gravity with Liouville-type
potentials for the dilaton field. These solutions have unusual
asymptotics--they are neither asymptotically flat nor asymptotically (anti-) de
Sitter. The solutions have one or two horizons hiding a curvature singularity
at the origin. A class of topological dyonic black holes with topology of a
torus is also presented. Some basic properties of the black holes are
discussed.Comment: LaTex, 10 pages; v2 changes in introduction, new references added; v3
new section with n-dimensional solutions is adde
Analytic Continuation for Asymptotically AdS 3D Gravity
We have previously proposed that asymptotically AdS 3D wormholes and black
holes can be analytically continued to the Euclidean signature. The analytic
continuation procedure was described for non-rotating spacetimes, for which a
plane t=0 of time symmetry exists. The resulting Euclidean manifolds turned out
to be handlebodies whose boundary is the Schottky double of the geometry of the
t=0 plane. In the present paper we generalize this analytic continuation map to
the case of rotating wormholes. The Euclidean manifolds we obtain are quotients
of the hyperbolic space by a certain quasi-Fuchsian group. The group is the
Fenchel-Nielsen deformation of the group of the non-rotating spacetime. The
angular velocity of an asymptotic region is shown to be related to the
Fenchel-Nielsen twist. This solves the problem of classification of rotating
black holes and wormholes in 2+1 dimensions: the spacetimes are parametrized by
the moduli of the boundary of the corresponding Euclidean spaces. We also
comment on the thermodynamics of the wormhole spacetimes.Comment: 28 pages, 14 figure
Black Hole Thermodynamics and Riemann Surfaces
We use the analytic continuation procedure proposed in our earlier works to
study the thermodynamics of black holes in 2+1 dimensions. A general black hole
in 2+1 dimensions has g handles hidden behind h horizons. The result of the
analytic continuation is a hyperbolic 3-manifold having the topology of a
handlebody. The boundary of this handlebody is a compact Riemann surface of
genus G=2g+h-1. Conformal moduli of this surface encode in a simple way the
physical characteristics of the black hole. The moduli space of black holes of
a given type (g,h) is then the Schottky space at genus G. The (logarithm of
the) thermodynamic partition function of the hole is the Kaehler potential for
the Weil-Peterson metric on the Schottky space. Bekenstein bound on the black
hole entropy leads us to conjecture a new strong bound on this Kaehler
potential.Comment: 17+1 pages, 9 figure
Pair Production of Topological anti de Sitter Black Holes
The pair creation of black holes with event horizons of non-trivial topology
is described. The spacetimes are all limiting cases of the cosmological
metric. They are generalizations of the dimensional black hole and have
asymptotically anti de Sitter behaviour. Domain walls instantons can mediate
their pair creation for a wide range of mass and charge.Comment: 4 pages, uses late
The Singularity Threshold of the Nonlinear Sigma Model Using 3D Adaptive Mesh Refinement
Numerical solutions to the nonlinear sigma model (NLSM), a wave map from 3+1
Minkowski space to S^3, are computed in three spatial dimensions (3D) using
adaptive mesh refinement (AMR). For initial data with compact support the model
is known to have two regimes, one in which regular initial data forms a
singularity and another in which the energy is dispersed to infinity. The
transition between these regimes has been shown in spherical symmetry to
demonstrate threshold behavior similar to that between black hole formation and
dispersal in gravitating theories. Here, I generalize the result by removing
the assumption of spherical symmetry. The evolutions suggest that the
spherically symmetric critical solution remains an intermediate attractor
separating the two end states.Comment: 5 pages, 5 figures, 1 table; To be published in Phys. Rev. D.; Added
discussion of initial data; Added figure and reference
Lattice Universes in 2+1-dimensional gravity
Lattice universes are spatially closed space-times of spherical topology in
the large, containing masses or black holes arranged in the symmetry of a
regular polygon or polytope. Exact solutions for such spacetimes are found in
2+1 dimensions for Einstein gravity with a non-positive cosmological constant.
By means of a mapping that preserves the essential nature of geodesics we
establish analogies between the flat and the negative curvature cases. This map
also allows treatment of point particles and black holes on a similar footing.Comment: 14 pages 7 figures, to appear in Festschrift for Vince Moncrief (CQG
The AdS/CFT Correspondence Conjecture and Topological Censorship
In gr-qc/9902061 it was shown that (n+1)-dimensional asymptotically
anti-de-Sitter spacetimes obeying natural causality conditions exhibit
topological censorship. We use this fact in this paper to derive in arbitrary
dimension relations between the topology of the timelike boundary-at-infinity,
\scri, and that of the spacetime interior to this boundary. We prove as a
simple corollary of topological censorship that any asymptotically anti-de
Sitter spacetime with a disconnected boundary-at-infinity necessarily contains
black hole horizons which screen the boundary components from each other. This
corollary may be viewed as a Lorentzian analog of the Witten and Yau result
hep-th/9910245, but is independent of the scalar curvature of \scri.
Furthermore, the topology of V', the Cauchy surface (as defined for
asymptotically anti-de Sitter spacetime with boundary-at-infinity) for regions
exterior to event horizons, is constrained by that of \scri. In this paper,
we prove a generalization of the homology results in gr-qc/9902061 in arbitrary
dimension, that H_{n-1}(V;Z)=Z^k where V is the closure of V' and k is the
number of boundaries interior to . As a consequence, V
does not contain any wormholes or other compact, non-simply connected
topological structures. Finally, for the case of n=2, we show that these
constraints and the onto homomorphism of the fundamental groups from which they
follow are sufficient to limit the topology of interior of V to either B^2 or
.Comment: Revtex, 20 page
A Note on the Positive Constant Curvature Space
We construct a positive constant curvature space by identifying some points
along a Killing vector in a de Sitter Space. This space is the counterpart of
the three-dimensional Schwarzschild-de Sitter solution in higher dimensions.
This space has a cosmological event horizon, and is of the topology , where denotes a -dimensional
conformal Minkowski spacetime.Comment: Revtex, 12 pages with two eps figures, to appear in PL
Constant Curvature Black Holes
Constant curvature black holes are constructed by identifying points in
anti-de Sitter space. In n dimensions, the resulting topology is R^{n-1} * S_1,
as opposed to the usual R^2 * S_{n-2} Schwarzschild black hole, and the
corresponding causal structure is displayed by a (n-1)-dimensional picture, as
opposed to the usual 2-dimensional Kruskal diagram. The five dimensional case,
which can be embedded in a Chern-Simons supergravity theory, is analyzed in
detail.Comment: New references added and some improvements in the presentation
introduced, 5 pages, 2 eps figures, REVTe
Logarithmic corrections to three-dimensional black holes and de Sitter spaces
We calculate logarithmic corrections to the Bekenstein-Hawking entropy for
three-dimensional BTZ black hole with J=0 and Kerr-de Sitter (KdS) space with
J=0 including the Schwarzschild-de Sitter (SdS) solution due to thermal
fluctuations. It is found that there is no distinction between the event
horizon of the BTZ black hole and the cosmological horizon of KdS space. We
obtain the same correction to the Cardy formula for BTZ, KdS, and SdS cases. We
discuss AdS/CFT and dS/ECFT correspondences in connection with logarithmic
corrections.Comment: 9 pages, version to appear in PLB. k-dependent analysis is withdraw
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