18 research outputs found
How hairy can a black ring be?
It has been shown recently that there is a large class of supersymmetric
solutions of five-dimensional supergravity which generalize the supersymmetric
black ring solution of Elvang et al. This class involves arbitrary functions.
We show that most of these solutions do not have smooth event horizons, so they
do not provide examples of black objects with infinite amounts of "hair".Comment: 19 pages. v2: minor change
Supersymmetric black rings and three-charge supertubes
We present supergravity solutions for 1/8-supersymmetric black supertubes
with three charges and three dipoles. Their reduction to five dimensions yields
supersymmetric black rings with regular horizons and two independent angular
momenta. The general solution contains seven independent parameters and
provides the first example of non-uniqueness of supersymmetric black holes. In
ten dimensions, the solutions can be realized as D1-D5-P black supertubes. We
also present a worldvolume construction of a supertube that exhibits three
dipoles explicitly. This description allows an arbitrary cross-section but
captures only one of the angular momenta.Comment: 59 pages, 6 figures; v2: minor correction
Small Horizons
All near horizon geometries of supersymmetric black holes in a N=2, D=5
higher-derivative supergravity theory are classified. Depending on the choice
of near-horizon data we find that either there are no regular horizons, or
horizons exist and the spatial cross-sections of the event horizons are
conformal to a squashed or round S^3, S^1 * S^2, or T^3. If the conformal
factor is constant then the solutions are maximally supersymmetric. If the
conformal factor is not constant, we find that it satisfies a non-linear vortex
equation, and the horizon may admit scalar hair.Comment: 21 pages, latex. Typos corrected and reference adde
All supersymmetric solutions of minimal supergravity in six dimensions
A general form for all supersymmetric solutions of minimal supergravity in
six dimensions is obtained. Examples of new supersymmetric solutions are
presented. It is proven that the only maximally supersymmetric solutions are
flat space, AdS_3 x S^3 and a plane wave. As an application of the general
solution, it is shown that any supersymmetric solution with a compact horizon
must have near-horizon geometry R^{1,1} x T^4, R^{1,1} x K3 or identified AdS_3
x S^3.Comment: 40 pages. v2: two references adde
Topology of supersymmetric N=1, D=4 supergravity horizons
All supersymmetric N=1, D=4 supergravity horizons have toroidal or spherical
topology, irrespective of whether the black hole preserves any supersymmetry.Comment: 17 pages, latex. Alterations to introduction and section 3.
Uniqueness of near-horizon geometries of rotating extremal AdS(4) black holes
We consider stationary extremal black hole solutions of the Einstein-Maxwell
equations with a negative cosmological constant in four dimensions. We
determine all non-static axisymmetric near-horizon geometries (with
non-toroidal horizon topology) and all static near-horizon geometries for black
holes of this kind. This allows us to deduce that the most general near-horizon
geometry of an asymptotically globally AdS(4) rotating extremal black hole, is
the near-horizon limit of extremal Kerr-Newman-AdS(4). We also identify the
subset of near-horizon geometries which are supersymmetric. Finally, we show
which physical quantities of extremal black holes may be computed from the
near-horizon limit alone, and point out a simple formula for the entropy of the
known supersymmetric AdS(4) black hole. Analogous results are presented in the
case of vanishing cosmological constant.Comment: 18 pages, Latex. v2: footnote added on pg. 12. v3: assumption of
non-toroidal horizon topology made explicit, minor clarification
The Kerr-Newman-Godel Black Hole
By applying a set of Hassan-Sen transformations and string dualities to the
Kerr-Godel solution of minimal D=5 supergravity we derive a four parameter
family of five dimensional solutions in type II string theory. They describe
rotating, charged black holes in a rotating background. For zero background
rotation, the solution is D=5 Kerr-Newman; for zero charge it is Kerr-Godel. In
a particular extremal limit the solution describes an asymptotically Godel BMPV
black hole.Comment: 12 pages, LaTeX, no figures; v2: one reference added, very minor
changes; to appear in CQ
Black holes in Goedel-type universes with a cosmological constant
We discuss supersymmetric black holes embedded in a Goedel-type universe with
cosmological constant in five dimensions. The spacetime is a fibration over a
four-dimensional Kaehler base manifold, and generically has closed timelike
curves. Asymptotically the space approaches a deformation of AdS_5, which
suggests that the appearance of closed timelike curves should have an
interpretation in some deformation of D=4, N=4 super-Yang-Mills theory.
Finally, a Goedel-de Sitter universe is also presented and its causal structure
is discussed.Comment: 25 pages, Latex, no figures, references updated, physical discussion
of the solutions considerably expanded, holographic stress tensor and
conserved charges of Goedel-AdS(5) solution compute
Supersymmetric Godel-type Universe in four Dimensions
We generalize the classification of all supersymmetric solutions of pure N=2,
D=4 gauged supergravity to the case when external sources are included. It is
shown that the source must be an electrically charged dust. We give a
particular solution to the resulting equations, that describes a Goedel-type
universe preserving one quarter of the supersymmetries.Comment: 6 pages, Latex. v2: references and footnote added. v3: introduction
expanded, minor corrections, references added. Final versio
Heterotic Black Horizons
We show that the supersymmetric near horizon geometry of heterotic black
holes is either an AdS_3 fibration over a 7-dimensional manifold which admits a
G_2 structure compatible with a connection with skew-symmetric torsion, or it
is a product R^{1,1} * S^8, where S^8 is a holonomy Spin(7) manifold,
preserving 2 and 1 supersymmetries respectively. Moreover, we demonstrate that
the AdS_3 class of heterotic horizons can preserve 4, 6 and 8 supersymmetries
provided that the geometry of the base space is further restricted. Similarly
R^{1,1} * S^8 horizons with extended supersymmetry are products of R^{1,1} with
special holonomy manifolds. We have also found that the heterotic horizons with
8 supersymmetries are locally isometric to AdS_3 * S^3 * T^4, AdS_3 * S^3 * K_3
or R^{1,1} * T^4 * K_3, where the radii of AdS_3 and S^3 are equal and the
dilaton is constant.Comment: 35 pages, latex. Minor alterations to equation (3.11) and section
4.1, the conclusions are not affecte