Supersymmetric Probes in a Rotating 5D Attractor

Supersymmetric zero-brane and one-brane probes in the squashed $AdS_2\times S^3$ near-horizon geometry of the BMPV black hole are studied. Supersymmetric zero-brane probes stabilized by orbital angular momentum on the $S^3$ are found and shown to saturate a BPS bound. We also find supersymmetric one-brane probes which have momentum and winding around a $U(1)_L\times U(1)_R$ torus in the $S^3$ and in some cases are static.Comment: 13 page

Supersymmetric Brane-Worlds

We present warped metrics which solve Einstein equations with arbitrary cosmological constants in both in upper and lower dimensions. When the lower-dimensional metric is the maximally symmetric one compatible with the chosen value of the cosmological constant, the upper-dimensional metric is also the maximally symmetric one and there is maximal unbroken supersymmetry as well. We then introduce brane sources and find solutions with analogous properties, except for supersymmetry, which is generically broken in the orbifolding procedure (one half is preserved in two special cases), and analyze metric perturbations in these backgrounds In analogy with the D8-brane we propose an effective $(\hat{d}-2)$-brane action which acts as a source for the RS solution. The action consists of a Nambu-Goto piece and a Wess-Zumino term containing a $(\hat{d}-1)$-form field. It has the standard form of the action for a BPS extended object, in correspondence with the supersymmetry preserved by the solution.Comment: 13 pages, Latex2e. Corrected and shortened version to appear in Phys. Lett.

Curved dilatonic brane-worlds and the cosmological constant problem

We construct a model for dilatonic brane worlds with constant curvature on the brane, i.e. a non-zero four-dimensional cosmological constant, given in function of the dilaton coupling and the cosmological constant of the bulk. We compare this family of solutions to other known dilatonic domain wall solutions and apply a self-tunning mechanism to check the stability of our solutions under quantum fluctuations living on the brane.Comment: latex, 6 pages. (v2): considerable changes in the conclusion. (v3): added new discussion on the solutions and some references; version to appear in CQ

The Near-Horizon Limit of the Extreme Rotating d=5 Black Hole as a Homogenous Spacetime

We show that the spacetime of the near-horizon limit of the extreme rotating d=5 black hole, which is maximally supersymmetric in N=2,d=5 supergravity for any value of the rotation parameter j in [-1,1], is locally isomorphic to a homogeneous non-symmetric spacetime corresponding to an element of the 1-parameter family of coset spaces SO(2,1)x SO(3)/SO(2)_j in which the subgroup SO(2)_j is a combination of the two SO(2) subgroups of SO(2,1) and SO(3).Comment: Some points clarified and misprints corrected. Version to be published in Classical and Quantum Gravit

E11 and Spheric Vacuum Solutions of Eleven- and Ten dimensional Supergravity Theories

In view of the newly conjectured Kac-Moody symmetries of supergravity theories placed in eleven and ten dimensions, the relation between these symmetry groups and possible compactifications are examined. In particular, we identify the relevant group cosets that parametrise the vacuum solutions of AdS x S type.Comment: discussion improve

Wrapped M2/M5 Duality

A microscopic accounting of the entropy of a generic 5D supersymmetric rotating black hole, arising from wrapped M2-branes in Calabi-Yau compactified M-theory, is an outstanding unsolved problem. In this paper we consider an expansion around the zero-entropy, zero-temperature, maximally rotating ground state for which the angular momentum J_L and graviphoton charge Q are related by J_L^2=Q^3. At J_L=0 the near horizon geometry is AdS_2 x S^3. As J_L^2 goes to Q^3 it becomes a singular quotient of AdS_3 x S^2: more precisely, a quotient of the near horizon geometry of an M5 wrapped on a 4-cycle whose self-intersection is the 2-cycle associated to the wrapped-M2 black hole. The singularity of the AdS_3 quotient is identified as the usual one associated to the zero-temperature limit, suggesting that the (0,4) wrapped-M5 CFT is dual near maximality to the wrapped-M2 black hole. As evidence for this, the microscopic (0,4) CFT entropy and the macroscopic rotating black hole entropy are found to agree to leading order away from maximality.Comment: 10 pages, no figure

Probe Brane Dynamics and the Cosmological Constant

Recently a brane world perspective on the cosmological constant and the hierarchy problems was presented. Here, we elaborate on some aspects of that particular scenario and discuss the stability of the stationary brane solution and the dynamics of a probe brane. Even though the brane is unstable under a small perturbation from its stationary position, such instability is harmless when the 4-D cosmological constant is very small, as is the case of our universe. One may also introduce radion stabilizing potentials in a more realistic scenario.Comment: 13 pages, 1 figure, REVTE

An Sl(3,R) multiplet of 8-dimensional type II supergravity theories and the gauged supergravity inside

The so-called ``massive 11-dimensional supergravity'' theory gives, for one Killing vector, Romans' massive 10-dimensional supergravity in 10 dimensions, for two Killing vectors an Sl(2,Z) multiplet of massive 9-dimensional supergravity theories that can be obtained by standard generalized dimensional reduction type IIB supergravity and has been shown to contain a gauged supergravity. We consider a straightforward generalization of this theory to three Killing vectors and a 3\times 3 symmetric mass matrix and show that it gives an Sl(3,Z) multiplet of 8-dimensional supergravity theories that contain an SO(3) gauged supergravity which is, in some way, the dual to the one found by Salam and Sezgin by standard generalized dimensional reduction.Comment: Latex2e, 20 pages, reference correcte