Patrick Meessen

An Sl(2, Z) multiplet of nine-dimensional type II supergravity theories

Abstract We show that only by performing generalized dimensional reductions all possible brane configurations are taken into account and one gets the complete lower-dimensional theory. We apply this idea to the reduction of type IIB supergravity in an SL (2, Z)-covariant way and establish T -duality for the type II superstring effective action in the context of generalized dimensional reduction giving the corresponding generalized Buschers T -duality rules. The full (generalized) dimensional reduction involves all the S -duals of D7-branes: Q7-branes and a sort of composite 7-branes. The three species constitute an SL (2, Z) triplet. Their presence induces the appearance of the triplet of masses of the 9-dimensional theory. The T -duals, including a “KK-8A-brane”, which must have a compact transverse dimension have to be considered in the type IIA side. Compactification of 11-dimensional KK-9M-branes (a.k.a. M9-branes) on the compact transverse dimension give D8-branes while compactification on a world-volume dimension gives KK-8A-branes. The presence of these KK-monopole-type objects breaks translation invariance and two of them given rise to an SL (2, Z)-covariant massive 11-dimensional supergravity whose reduction gives the massive 9-dimensional type II theories.

The supersymmetric configurations of N = 2, d = 4 supergravity coupled to vector supermultiplets

We classify all the supersymmetric configurations of ungauged N = 2, d = 4 supergravity coupled to n vector multiplets and determine under which conditions they are also classical solutions of the equations of motion. The supersymmetric configurations fall into two classes, depending on the timelike or null nature of the Killing vector constructed from Killing spinor bilinears. The timelike class configurations are ∗ ] ,

Supergravity solutions for D-branes in Hpp-wave backgrounds

We derive two families of supergravity solutions describing D-branes in the maximally supersymmetric Hpp-wave background. The first family of solutions corresponds to quarter-BPS D-branes. These solutions are delocalised along certain directions transverse to the pp-wave. The second family corresponds to the non-supersymmetric D-branes. These solutions are fully localised. A peculiar feature of the nonsupersymmetric solutions is that gravity becomes repulsive close to the core of the D-brane. Both families preserve the amount of supersymmetry predicted by the D-brane probe/CFT analysis. All solutions are written in Brinkman coordinates. To construct these kind of solutions it is crucial to identify the coordinates in which the ansatz looks the simplest. We argue that the natural coordinates to get the supergravity description of the half-BPS branes are the Rosen coordinates.We derive two families of supergravity solutions describing D-branes in the maximally supersymmetric Hpp-wave background. The first family of solutions corresponds to quarter-BPS D-branes. These solutions are delocalized along certain directions transverse to the pp-wave. The second family corresponds to the non-supersymmetric D-branes. These solutions are fully localized. A peculiar feature of the non-supersymmetric solutions is that gravity becomes repulsive close to the core of the D-brane. Both families preserve the amount of supersymmetry predicted by the D-brane probe/CFT analysis. All solutions are written in Brinkman coordinates. To construct these kinds of solutions it is crucial to identify the coordinates in which the ansatz looks the simplest. We argue that the natural coordinates to get the supergravity description of the half-BPS branes are the Rosen coordinates.

Supersymmetry and homogeneity of M-theory backgrounds

We describe the construction of a Lie superalgebra associated with an arbitrary supersymmetric M-theory background, and discuss some examples. We prove that for backgrounds with more than 24 supercharges, the bosonic subalgebra acts locally transitively. In particular, we prove that backgrounds with more than 24 supersymmetries are necessarily (locally) homogeneous. Furthermore we provide evidence that 24 is the minimal number of supersymmetries which guarantees this.

Supersymmetry of topological Kerr-Newman-Taub- NUT-adS spacetimes

We extend the topological Kerr-Newman-adS solutions by including NUT charge and find generalizations of the Robinson-Bertotti solution to the negative cosmological constant case with different topologies. We show how all of these solutions can be obtained as limits of the general Plebanski-Demianski solution. We study the supersymmetry properties of all these solutions in the context of gauged N = 2, d = 4 supergravity. Generically they preserve, at most, quarter of the total supersymmetry. In the Plebanski-Demianski case, although gauged N = 2, d = 4 supergravity does not have electro-magnetic duality, we find that the family of supersymmetric solutions still exhibits an electro-magnetic duality in which electric and magnetic charges and mass and Taub-NUT charge are rotated simultaneously.

All the supersymmetric solutions of N = 1, d = 5 ungauged supergravity

We classify the supersymmetric solutions of ungauged N = 1 d = 5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstr?m black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N = 2, d = 4 solutions. Our formulae allows the uplifting of certain N = 2, d = 4 black holes to N = 1, d = 5 black holes on KK monopoles or to pp-waves propagating along black strings.

Supersymmetric N = 2 Einstein-Yang-Mills monopoles and covariant attractors

We present two generic classes of supersymmetric solutions of N = 2, d = 4 supergravity coupled to non-Abelian vector supermultiplets with a gauge group that includes an SU(2) factor. The first class consists of embeddings of the ’t HooftPolyakov monopole and in the examples considered it has a fully regular, asymptotically flat space-time metric without event horizons. The other class of solutions consists of regular non-Abelian extreme black holes. There is a covariant attractor at the horizon of these non-Abelian black holes.

Supersymmetric solutions of N=2, D=4 SUGRA: The whole ungauged shebang

Abstract In this article we complete the classification of the supersymmetric solutions of N = 2 , D = 4 ungauged supergravity coupled to an arbitrary number of vector- and hypermultiplets. We find that in the timelike case the hypermultiplets cause the constant-time hypersurfaces to be curved and have SU ( 2 ) holonomy identical to that of the hyperscalar manifold. The solutions have the same structure as without hypermultiplets but now depend on functions which are harmonic in the curved 3-dimensional space. We discuss an example obtained from a hyper-less solution via the c-map. In the null case we find that the hyperscalars can only depend on the null coordinate and the solutions are essentially those of the hyper-less case.

HOMOGENEITY AND PLANE-WAVE LIMITS

We explore the plane-wave limit of homogeneous spacetimes. For plane-wave limits along homogeneous geodesics the limit is known to be ho- mogeneous and we exhibit the limiting metric in terms of Lie algebraic data. This simplifies many calculations and we illustrate this with several examples. We also investigate the behaviour of (reductive) homogeneous structures under the plane-wave limit.

Small note on pp -wave vacua in 6 and 5 dimensions

We discuss Kowalski-Glikman type pp-wave solutions with unbroken supersymmetry in 6 and 5 dimensional supergravity theories.