Concentric Black Rings

We present new supersymmetric solutions of five-dimensional minimal supergravity that describe concentric black rings with an optional black hole at the common centre. Configurations of two black rings are found which have the same conserved charges as a single rotating black hole; these black rings can have a total horizon area less than, equal to, or greater than the black hole with the same charges. A numerical investigation of these particular black ring solutions suggests that they do not have closed timelike curves.Comment: 7 pages, minor alterations, typos corrected. Version to be published in PR

On Non-extremal Instantons and Black Holes

We consider a general analysis and a specific ansatz for the study of non-supersymmetric solutions in arbitrary dimensions and various metric signatures. In all cases, we find that the conditions on the solutions can be written in terms of quadratic forms involving the gauge coupling of the theory and constants of integration associated with the scalar fields. Depending on the signature of the metric, our analysis should provide a general framework for finding non-extremal black holes, instantons, branes and S-branes.Comment: 19 page

Null Half-Supersymmetric Solutions in Five-Dimensional Supergravity

We classify half-supersymmetric solutions of gauged N=2, D=5 supergravity coupled to an arbitrary number of abelian vector multiplets for which all of the Killing spinors generate null Killing vectors. We show that there are four classes of solutions, and in each class we find the metric, scalars and gauge field strengths. When the scalar manifold is symmetric, the solutions correspond to a class of local near horizon geometries recently found by Kunduri and Lucietti.Comment: 46 pages, typos corrected and reference added. Section 7.1 has been added: it is shown that the solutions found here correspond to a class of solutions found in arXiv:0708.3695. Uses JHEP3.cl

General Concentric Black Rings

Supersymmetric black ring solutions of five dimensional supergravity coupled to an arbitrary number of vector multiplets are constructed. The solutions are asymptotically flat and describe configurations of concentric black rings which have regular horizons with topology $S^1 \times S^2$ and no closed time-like curves at the horizons.Comment: 8 pages, minor alterations, typos corrected. Version to be published in PR

Non-Supersymmetric Charged Domain Walls

We present general non-supersymmtric domain wall solutions with non-trivial scalar and gauge fields for gauged five-dimensional N=2 supergravity coupled to abelian vector multiplets.Comment: 11 pages, one ref. added. To appear in Physics Letters

Vanishing Preons in the Fifth Dimension

We examine supersymmetric solutions of N=2, D=5 gauged supergravity coupled to an arbitrary number of abelian vector multiplets using the spinorial geometry method. By making use of methods developed in hep-th/0606049 to analyse preons in type IIB supergravity, we show that there are no solutions preserving exactly 3/4 of the supersymmetry.Comment: 19 pages, latex. Reference added, and further modification to the introductio

Uniqueness of Five-Dimensional Supersymmetric Black Holes

A classification of supersymmetric solutions of five dimensional ungauged supergravity coupled to arbitrary many abelian vector multiplets is used to prove a uniqueness theorem for asymptotically flat supersymmetric black holes with regular horizons. It is shown that the near-horizon geometries of solutions for which the scalars and gauge field strengths are sufficiently regular on the horizon are flat space, AdS_3 x S^2, or the near-horizon BMPV solution. Furthermore, the only black hole which has the near-horizon BMPV geometry for its near-horizon geometry is the solution found by Chamseddine and Sabra.Comment: 15 pages, uses JHEP3.cls. Revised to match published version; reference added, minor alterations to section

Einstein Weyl Structures and de Sitter Supergravity

The geometric structure of the null solutions of de Sitter D=5 gauged supergravity coupled to vector multiplets is investigated. These solutions are Kundt metrics, constructed from a one-parameter family of three dimensional Gauduchon-Tod base spaces. We give examples, including the near horizon geometries previously found in arxiv:hep-th/10122120. In addition, two special cases are considered in detail. In the first, we consider solutions for which the Gauduchon-Tod base space is the Berger sphere. In the second case we take the null 1-form Killing spinor bilinear to be recurrent, so that the holonomy of the Levi-Civita connection is contained in Sim(3).Comment: 23 page

Maximally Minimal Preons in Four Dimensions

Killing spinors of N=2, D=4 supergravity are examined using the spinorial geometry method, in which spinors are written as differential forms. By making use of methods developed in hep-th/0606049 to analyze preons in type IIB supergravity, we show that there are no simply connected solutions preserving exactly 3/4 of the supersymmetry.Comment: 18 pages. References added, comments added discussing the possibility of discrete quotients of AdS(4) preserving 3/4 supersymmetry

Five Dimensional Minimal Supergravities and Four Dimensional Complex Geometries

We discuss the relation between solutions admitting Killing spinors of minimal supergravities in five dimensions and four dimensional complex geometries. In the ungauged case (vanishing cosmological constant \Lambda=0) the solutions are determined in terms of a hyper-Kahler base space; in the gauged case (\Lambda<0) the complex geometry is Kahler; in the de Sitter case (\Lambda>0) the complex geometry is hyper-Kahler with torsion (HKT). In the latter case some details of the derivation are given. The method for constructing explicit solutions is discussed in each case.Comment: 8 pages. Contribution to the Proceedings of the Spanish Relativity Meeting 2008 in Salamanca, Spai