Multi-black rings and the phase diagram of higher-dimensional black holes

Configurations of multiple concentric black rings play an important role in determining the pattern of branchings, connections and mergers between different phases of higher-dimensional black holes. We examine them using both approximate and (in five dimensions) exact methods. By identifying the role of the different scales in the system, we argue that it is possible to have multiple black ring configurations in which all the rings have equal temperature and angular velocity. This allows us to correct and improve in a simple, natural manner, an earlier proposal for the phase diagram of singly-rotating black holes in $D\geq 6$.Comment: 14 pages, 2 figure

Braneworlds and Dark Energy

In the Randall-Sundrum scenario, we analyse the dynamics of an AdS5 braneworld when conformal matter fields propagate in five dimensions. We show that conformal fields of weight -4 are associated with stable geometries which describe the dynamics of inhomogeneous dust, generalized dark radiation and homogeneous polytropic dark energy on a spherically symmetric 3-brane embedded in the compact AdS5 orbifold. We discuss aspects of the radion stability conditions and of the localization of gravity in the vicinity of the brane.Comment: 12 pages, latex, 3 eps figures. Talk given at the Seventh Workshop on Quantum Field Theory under the Influence of External Conditions, IEEC, CSIC and University of Barcelona, Barcelona, Catalonia, Spain, 5-9 September 2005. Revised version published in the workshop proceedings, J. Phys. A: Mathematical and General. Typos corrected and some changes introduced for clarit

Pressure in Chern-Simons Field Theory to Three-Loop Order

We calculate perturbatively the pressure of a dilute gas of anyons through second order in the anyon coupling constant, as described by Chern-Simons field theory. Near Bose statistics , the divergences in the perturbative expansion are exactly cancelled by a two-body $\delta$-function potential which is not required near Fermi statistics. To the order considered, we find no need for a non-hermitian Hamiltonian. (This paper precedes the article ''Three loop calculation of the full anyonic partition function'', by R. Emparan and M. Valle Basagoiti, hep-th/9304103)Comment: 10 pages, PlainTeX with macro manumac (included), report EHU-FT-92/

Cutoff AdS/CFT duality and the quest for braneworld black holes

We present significant evidence in favour of the holographic conjecture that ``4D black holes localized on the brane found by solving the classical bulk equations in $AdS_5$ are quantum corrected black holes and not classical ones''. The crucial test is the calculation of the quantum correction to the Newtonian potential based on a numerical computation of in Schwarzschild spacetime for matter fields in the zero temperature Boulware vacuum state. For the case of the conformally invariant scalar field the leading order term is found to be $M/45\pi r^3$. This result is equivalent to the result which was previously obtained in the weak-field approximation using Feynman diagrams and which has been shown to be equivalent, via the AdS/CFT duality, to the analogous calculation in Randall-Sundrum braneworlds. This asymptotic behavior was not captured in the analytical approximations for proposed in the literature. The 4D backreaction equations are then used to make a prediction about the existence and the possible spacetime structure of macroscopic static braneworld black holes.Comment: 4 pages, 2 figure

Blackfolds in (Anti)-de Sitter Backgrounds

We construct different neutral blackfold solutions in Anti-de Sitter and de Sitter background spacetimes in the limit where the cosmological scale is taken to be much larger than the transverse horizon size. This includes a class of blackfolds with horizons that are products of odd-spheres times a transverse sphere, for which the thermodynamic stability is also studied. Moreover, we exhibit a specific case in which the same blackfold solution can describe different limiting black hole spacetimes therefore illustrating the geometric character of the blackfold approach. Furthermore, we show that the higher-dimensional Kerr-(Anti)-de Sitter black hole allows for ultra-spinning regimes in the relevant limit of large cosmological scale, and demonstrate that this is correctly described by a pancaked blackfold geometry. We also give evidence for the possibility of saturating the rigidity theorem in these backgrounds.Comment: v1: 1+29 pages, latex. v2: cosmetic changes. v3: .pdf file correcte

Derivation of the blackfold effective theory

We study fluctuations and deformations of black branes over length scales larger than the horizon radius. We prove that the Einstein equations for the perturbed p-brane yield, as constraints, the equations of the effective blackfold theory. We solve the Einstein equations for the perturbed geometry and show that it remains regular on and outside the black brane horizon. This study provides an ab initio derivation of the blackfold effective theory and gives explicit expressions for the metrics near the new black holes and black branes that result from it, to leading order in a derivative expansion.Comment: 20 pages. v4: Typo corrected in eq. (6.11) -- erratum in the published versio

Simple solutions to the Einstein Equations in spaces with unusual topology

We discuss simple vacuum solutions to the Einstein Equations in five dimensional space-times compactified in two different ways. In such spaces, one black hole phase and more then one black string phase may exist. Several old metrics are adapted to new background topologies to yield new solutions to the Einstein Equations. We then briefly talk about the angular momentum they may carry, the horizon topology and phase transitions that may occur.Comment: Published versions. Includes referee input. 10 pages, 3 figure

Exact constraints on D≤10\leq 10 Myers Perry black holes and the Wald Problem

Exact relations on the existence of event horizons of Myers Perry black holes are obtained in $D\leq 10$ dimensions. It is further shown that naked singularities can not be produced by "spinning-up" these black holes by shooting particles into their $\lfloor\frac{D-1}{2}\rfloor$ equatorial planes.Comment: 7 pages, 11 figures, version two corrects an earlier error in equation (35) and adds some plots for cohomogeneity-2 and 3 black hole