We report on a campaign of X-ray and soft γ-ray observations of the black hole candidate H 1743-322 (also named IGR J17464-3213), performed with the RXTE, INTEGRAL and Swift satellites. The source was observed during a short outburst between 2008 October 03 and 2008 November 16. The evolution of the hardness-intensity diagram throughout the outburst is peculiar, in that it does not follow the c...

We study the gravitational collapse of a self-gravitating charged scalar-field. Starting with a regular spacetime, we follow the evolution through the formation of an apparent horizon, a Cauchy horizon and a final central singularity. We find a null, weak, mass-inflation singularity along the Cauchy horizon, which is a precursor of a strong, spacelike singularity along the r = 0 hypersurface. T...

We develop a method for computing the free-energy of a canonical ensemble of quantum fields near the horizon of a rotating black hole. We show that the density of energy levels of a quantum field on a stationary background can be related to the density of levels of the same field on a fiducial static space-time. The effect of the rotation appears in the additional interaction of the ”static” fi...

The isolated horizons formalism [1] has been used to formulate several conjectures regarding static black holes [2],[3]. In this article we study the static, spherically symmetric Einstein-Skyrme black hole solutions first found in [4],[5],[6]. The Einstein-Skyrme solutions have a number of features that, while generic to certain models involving non-abelian gauge fields [7], are not features o...

We argue that the configurations of maximal entropy in five-dimensional asymptotically flat vacuum gravity, for fixed mass and angular momentum, are ‘black Saturns’ with a central, close to static, black hole and a very thin black ring around it. For any value of the angular momentum, the upper bound on the entropy is equal to the entropy of a static black hole of the same total mass. For fixed...