2,051 research outputs found
BPS Geometries and AdS Bubbles
Recently, 1/2-BPS AdS bubble solutions have been obtained by Lin, Lunin and
Maldacena, which correspond to Fermi droplets in phase space in the dual CFT
picture. They can be thought of as generalisations of 1/2-BPS AdS black hole
solutions in five or seven dimensional gauged supergravity. In this paper, we
extend these solutions by invoking additional gauge fields and scalar fields in
the supergravity Lagrangians, thereby obtaining AdS bubble generalisations of
the previously-known multi-charge AdS black solutions of gauged supergravity.
We also obtain analogous AdS bubble solutions in four-dimensional gauged
supergravity. Our solutions generically preserve supersymmetry fractions 1/4,
1/8 and 1/8 in seven, five and four dimensions respectively. They can be lifted
to M-theory or type IIB string theory, using previously known formulae for the
consistent Pauli sphere reductions that yield the gauged supergravities. We
also find similar solutions in six-dimensional gauged supergravity, and discuss
their lift to the massive type IIA theory.Comment: Latex, 11 page
Charged Rotating Black Holes in Four-Dimensional Gauged and Ungauged Supergravities
We study four-dimensional non-extremal charged rotating black holes in
ungauged and gauged supergravity. In the ungauged case, we obtain rotating
black holes with four independent charges, as solutions of N=2 supergravity
coupled to three abelian vector multiplets. This is done by reducing the theory
along the time direction to three dimensions, where it has an O(4,4) global
symmetry. Applied to the reduction of the uncharged Kerr metric,
O(1,1)^4\subset O(4,4) transformations generate new solutions that correspond,
after lifting back to four dimensions, to the introduction of four independent
electromagnetic charges. In the case where these charges are set pairwise
equal, we then generalise the four-dimensional rotating black holes to
solutions of gauged N=4 supergravity, with mass, angular momentum and two
independent electromagnetic charges. The dilaton and axion fields are
non-constant. We also find generalisations of the gauged and ungauged solutions
to include the NUT parameter, and for the ungauged solutions, the acceleration
parameter too. The solutions in gauged supergravity provide new gravitational
backgrounds for a further study of the AdS_4/CFT_3 correspondence at non-zero
temperature.Comment: Latex, 30 page
Ghost-Free de Sitter Supergravities as Consistent Reductions of String and M-theory
We study properties of supergravity theories with non-compact gaugings, and
their higher-dimensional interpretations via consistent reductions on the
inhomogeneous non-compact hyperboloidal spaces {\cal H}^{p,q}. The gauged
supergravities are free of ghosts, despite the non-compactness of the gauge
groups. We give a general discussion of the existence of stationary points in
the scalar potentials of such supergravities. These are of interest since they
can be associated with de Sitter vacuum configurations. We give explicit
results for consistent reductions on {\cal H}^{p,q} in various examples,
derived from analytic continuation of previously-known consistent sphere
reductions. In addition we also consider black hole and cosmological solutions,
for specific examples of non-compact gaugings in D=4,5,7.Comment: Latex, 35 page
Supersymmetric Domain-Wall World from D=5 Simple Gauged Supergravity
We address a supersymmetric embedding of domain walls with asymptotically
anti-deSitter (AdS) space-times in five-dimensional simple, N=2 U(1) gauged
supergravity theory constructed by Gunaydin, Townsend and Sierra. These
conformally flat solutions interpolate between supersymmetric AdS vacua,
satisfy the Killing spinor (first order) differential equations, and the
four-dimensional world on the domain wall is a flat world with N=1
supersymmetry. Regular solutions in this class have the energy density related
to the cosmological constants of the supersymmetric AdS vacua. An analysis of
such solutions is given for the example of one (real, neutral) vector
supermultiplet with the most general form of the prepotential. There are at
most two supersymmetric AdS vacua that are in general separated by a
singularity in the potential. Nevertheless the supersymmetric domain wall
solution exists with the scalar field interpolating continuously across the
singular region.Comment: 12 pages, LaTeX, sign corrected, resulting in a different asymptotics
for the exampl
Extreme Domain Wall--Black Hole Complementarity in N=1SUPERGRAVITY with a General Dilaton Coupling
We study supersymmetric (extreme) domain walls in four-dimensional (4d) N=1
supergravity theories with a general dilaton coupling . Type I
walls, which are static, planar (say, in () plane) configurations,
interpolate between Minkowski space-time and a vacuum with a varying dilaton
field. We classify their global space-time with respect to the value of the
coupling . supergravity with , an effective theory
from superstrings, provides a dividing line between the theories with
, where there is a naked (planar) singularity on one side of the
wall, and the theories with , where the singularity of the of the
wall is covered by the horizon. The global space-time (in ) direction) of
the extreme walls with the coupling is the same as the global
space-time (in ( direction) of the extreme magnetically charged black
holes with the coupling .Comment: 11 pages (3 figures available from
ftp://dept.physics.upenn.edu/pub/UPR-600-T/), UPR-600-T revised to be
compatible with the published versio
New G_2 metric, D6-branes and Lattice Universe
We construct a new (singular) cohomogeneity-three metric of G_2 holonomy. The
solution can be viewed as a triple intersection of smeared Taub-NUTs. The
metric comprises three non-compact radial-type coordinates, with the principal
orbits being a T^3 bundle over S^1. We consider an M-theory vacuum
(Minkowski)_4\times M_7 where M_7 is the G_2 manifold. Upon reduction on a
circle in the T^3, we obtain the intersection of a D6-brane, a Taub-NUT and a
6-brane with R-R 2-form flux. Reducing the solution instead on the base space
S^1, we obtain three intersecting 6-branes all carrying R-R 2-form flux. These
two configurations can be viewed as a classical flop in the type IIA string
theory. After reducing on the full principal orbits and the spatial
world-volume, we obtain a four-dimensional metric describing a lattice
universe, in which the three non-compact coordinates of the G_2 manifold are
identified with the spatial coordinates of our universe.Comment: Latex, 8 page
Consistent Sphere Reductions and Universality of the Coulomb Branch in the Domain-Wall/QFT Correspondence
We prove that any D-dimensional theory comprising gravity, an antisymmetric
n-index field strength and a dilaton can be consistently reduced on S^n in a
truncation in which just scalar fields and the metric are retained in
(D-n)-dimensions, provided only that the strength of the couping of the dilaton
to the field strength is appropriately chosen. A consistent reduction can then
be performed for n\le 5; with D being arbitrary when n\le 3, whilst D\le 11 for
n=4 and D\le 10 for n=5. (Or, by Hodge dualisation, can be replaced by
(D-n) in these conditions.) We obtain the lower dimensional scalar potentials
and construct associated domain wall solutions. We use the consistent reduction
Ansatz to lift domain-wall solutions in the (D-n)-dimensional theory back to D
dimensions, where we show that they become certain continuous distributions of
(D-n-2)-branes. We also examine the spectrum for a minimally-coupled scalar
field in the domain-wall background, showing that it has a universal structure
characterised completely by the dimension n of the compactifying sphere.Comment: latex file, 21 pages, 1 figure, minor typo correction
Non-extremal Charged Rotating Black Holes in Seven-Dimensional Gauged Supergravity
We obtain the solution for non-extremal charged rotating black holes in
seven-dimensional gauged supergravity, in the case where the three rotation
parameters are set equal. There are two independent charges, corresponding to
gauge fields in the U(1)xU(1) abelian subgroup of the SO(5) gauge group. A new
feature in these solutions, not seen previously in lower-dimensional examples,
is that the first-order "odd-dimensional self-duality" equation for the 4-form
field strength plays a non-trivial role. We also study the BPS limit of our
solutions where the black holes become supersymmetric. Our results are of
significance for the AdS_7/CFT_6 correspondence in M-theory.Comment: Latex, 12 pages, typos corrected and a reference adde
Supersymmetric Composite Models on Intersecting D-branes
We construct supersymmetric composite models of quarks and leptons from type
IIA T^6/(Z_2 x Z_2) orientifolds with intersecting D6-branes. In case of T^6 =
T^2 x T^2 x T^2 with no tilted T^2, a composite model of the supersymmetric
SU(5) grand unified theory with three generations is constructed. In case of
that one T^2 is tilted, a composite model with SU(3)_c x SU(2)_L x U(1)_Y gauge
symmetry with three generations is constructed. These models are not realistic,
but contain fewer additional exotic particles and U(1) gauge symmetries due to
the introduction of the compositeness of quarks and leptons. The masses of some
exotic particles are naturally generated through the Yukawa interactions among
"preons".Comment: 15 pages, 2 figure
Non-Extremal Rotating Black Holes in Five-Dimensional Gauged Supergravity
Supersymmetric black holes in five-dimensional gauged supergravity must
necessarily be rotating, and so in order to study the passage to black holes
away from supersymmetry, it is of great interest to obtain non-extremal black
holes that again have non-zero rotation. In this paper we find a simple
framework for describing non-extremal rotating black holes in five-dimensional
gauged supergravities. Using this framework, we are able to construct a new
solution, describing the general single-charge solution of N=2 gauged
supergravity, with arbitrary values for the two rotation parameters.
Previously-obtained solutions with two or three equal charges also assume a
much simpler form in the new framework, as also does the general solution with
three unequal charges in ungauged N=2 supergravity. We discuss the
thermodynamics and BPS limit of the new single-charge solutions, and we discuss
the separability of the Hamilton-Jacobi and Klein-Gordan equations in these
backgrounds.Comment: Latex, 12 pages. Mis-statement about separability of Hamilton-Jacobi
and Klein-Gordon equations correcte
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