It has been proposed that translationally invariant black branes are classically stable if and only if they are locally thermodynamically stable. Reall has outlined a general argument to demonstrate this, and studied in detail the case of charged black p-branes in type II supergravity. We consider the application of his argument in the simplest nontrivial case, an uncharged asymptotically flat brane enclosed in a finite cylindrical cavity. In this simple context, it is possible to give a more complete argument than in the cases considered earlier, and it is therefore a particularly attractive example of the general approach.

We use a new, exact approach in calculating the energy density measured by an observer living on a brane embedded in a charged black hole spacetime. We find that the bulk Weyl tensor gives rise to non-linear terms in the energy density and pressure in the FRW equations for the brane. Remarkably, these take exactly the same form as the "unconventional" terms found in the cosmology of branes embedded in pure AdS, with extra matter living on the brane. Black hole driven cosmologies have the benefit that there is no ambiguity in splitting the braneword energy momentum into tension and additional matter. We propose a new, enlarged relationship between the two descriptions of braneworld cosmology. We also study the exact thermodynamics of the field theory and present a generalised Cardy-Verlinde formula in this set up. * J.P.Gregory@durham.ac.uk † Antonio.Padilla@durham.ac.uk

We construct a five-dimensional, asymptotically Gödel, three-charge black hole via dimensional reduction of an asymptotically plane wave, rotating D1-D5-brane solution of type IIB supergravity. This latter is itself constructed via the solution generating procedure of Garfinkle and Vachaspati, applied to the standard rotating D1-D5-brane solution. Taking all charges to be equal gives a "BMPV Gödel black hole", which is closely related to that recently found by Herdeiro. We emphasise, however, the importance of our ten-dimensional microscopic description in terms of branes. We discuss various properties of the asymptotically Gödel black hole, including the physical bound on the rotation of the hole, the existence of closed timelike curves, and possible holographic protection of chronology.

Recently, it has been proposed that the deformed matrix model describes a twodimensional type 0A extremal black hole. In this paper, the thermodynamics of 0A charged non-extremal black holes is investigated. We observe that the free energy of the deformed matrix model to leading order in 1/q can be seen to agree to that of the extremal black hole. We also speculate on how the deformed matrix model is able to describe the thermodynamics of non-extremal black holes.

We investigate holography on an (n − 1)-dimensional brane embedded in a background of AdS black holes, in n-dimensional Gauss-Bonnet gravity. We demonstrate that for a critical brane near the AdS boundary, the Friedmann equation corresponds to that of the standard cosmology driven by a CFT dual to the AdS bulk. We show that there is no holographic description for noncritical branes, or when the brane is further away from the AdS boundary. We then derive a Cardy-Verlinde formula for the dual CFT on the critical brane near the boundary. This gives us insight into the remarkable correspondence between Cardy-Verlinde formulae and Friedmann equations in Einstein gravity. * James.Gregory@teorfys.uu.se † a.padilla1@physics.ox.ac.uk