6 research outputs found
Spacetime singularity resolution by M-theory fivebranes: calibrated geometry, Anti-de Sitter solutions and special holonomy metrics
The supergravity description of various configurations of supersymmetric
M-fivebranes wrapped on calibrated cycles of special holonomy manifolds is
studied. The description is provided by solutions of eleven-dimensional
supergravity which interpolate smoothly between a special holonomy manifold and
an event horizon with Anti-de Sitter geometry. For known examples of Anti-de
Sitter solutions, the associated special holonomy metric is derived. One
explicit Anti-de Sitter solution of M-theory is so treated for fivebranes
wrapping each of the following cycles: K\"{a}hler cycles in Calabi-Yau two-,
three- and four-folds; special lagrangian cycles in three- and four-folds;
associative three- and co-associative four-cycles in manifolds; complex
lagrangian four-cycles in manifolds; and Cayley four-cycles in
manifolds. In each case, the associated special holonomy metric is
singular, and is a hyperbolic analogue of a known metric. The analogous known
metrics are respectively: Eguchi-Hanson, the resolved conifold and the
four-fold resolved conifold; the deformed conifold, and the Stenzel four-fold
metric; the Bryant-Salamon-Gibbons-Page-Pope metrics on an
bundle over , and an bundle over or ;
the Calabi hyper-K\"{a}hler metric on ; and the
Bryant-Salamon-Gibbons-Page-Pope metric on an bundle
over . By the AdS/CFT correspondence, a conformal field theory is
associated to each of the new singular special holonomy metrics, and defines
the quantum gravitational physics of the resolution of their singularities.Comment: 1+52 page
General Supersymmetric Solutions of Five-Dimensional Supergravity
The classification of 1/4-supersymmetric solutions of five dimensional gauged
supergravity coupled to arbitrary many abelian vector multiplets, which was
initiated in hep-th/0401129, is completed. The structure of all solutions for
which the Killing vector constructed from the Killing spinor is null is
investigated in both the gauged and the ungauged theories and some new
solutions are constructed.Comment: 24 pages, references added, uses JHEP3.cl
Supersymmetric AdS_3, AdS_2 and Bubble Solutions
We present new supersymmetric AdS_3 solutions of type IIB supergravity and
AdS_2 solutions of D=11 supergravity. The former are dual to conformal field
theories in two dimensions with N=(0,2) supersymmetry while the latter are dual
to conformal quantum mechanics with two supercharges. Our construction also
includes AdS_2 solutions of D=11 supergravity that have non-compact internal
spaces which are dual to three-dimensional N=2 superconformal field theories
coupled to point-like defects. We also present some new bubble-type solutions,
corresponding to BPS states in conformal theories, that preserve four
supersymmetries.Comment: v2: 33 pages, published version in JHE
1/4-BPS M-theory bubbles with SO(3) x SO(4) symmetry
In this paper we generalize the work of Lin, Lunin and Maldacena on the
classification of 1/2-BPS M-theory solutions to a specific class of 1/4-BPS
configurations. We are interested in the solutions of 11 dimensional
supergravity with symmetry, and it is shown that such
solutions are constructed over a one-parameter familiy of 4 dimensional almost
Calabi-Yau spaces. Through analytic continuations we can obtain M-theory
solutions having or factors. It is shown
that our result is equivalent to the solutions which have been recently
reported as the near-horizon geometry of M2 or M5-branes wrapped on 2 or
4-cycles in Calabi-Yau threefolds. We also discuss the hierarchy of M-theory
bubbles with different number of supersymmetries.Comment: 22 pages, JHEP3.cls; v2. revised version. showed that our results
agree with previous works hep-th/0605146 and hep-th/061219
Geometries with Killing Spinors and Supersymmetric AdS Solutions
The seven and nine dimensional geometries associated with certain classes of
supersymmetric and solutions of type IIB and D=11 supergravity,
respectively, have many similarities with Sasaki-Einstein geometry. We further
elucidate their properties and also generalise them to higher odd dimensions by
introducing a new class of complex geometries in dimensions, specified
by a Riemannian metric, a scalar field and a closed three-form, which admit a
particular kind of Killing spinor. In particular, for , we show that
when the geometry in dimensions is a cone we obtain a class of
geometries in dimensions, specified by a Riemannian metric, a scalar
field and a closed two-form, which includes the seven and nine-dimensional
geometries mentioned above when , respectively. We also consider various
ansatz for the geometries and construct infinite classes of explicit examples
for all .Comment: 28 page
1/2-BPS states in M theory and defects in the dual CFTs
We study supersymmetric branes in AdS_7 x S^4 and AdS_4 x S^7. We show that
in the former case the membranes should be viewed as M5 branes with fluxes and
we identify two types of such fivebranes (they are analogous to giant gravitons
and to dual giants). In AdS_4 x S^7 we find both M5 branes with fluxes and
freestanding stacks of membranes. We also go beyond probe approximation and
construct regular supergravity solutions describing geometries produced by the
branes. The metrics are completely specified by one function which satisfies
either Laplace or Toda equation and we give a complete classification of
boundary conditions leading to smooth geometries. The brane configurations
discussed in this paper are dual to various defects in three- and
six-dimensional conformal field theories.Comment: 82 pages, 12 figures, added ref