Stringy Stability of Dilaton Black Holes in 5-Dimensional Anti-de Sitter Space

Flat electrical charged black holes in 5-dimensional anti-de Sitter space have been applied to the study of the phase diagram of quark matter via AdS/CFT correspondence. In such application it is argued that since the temperature of the quark gluon plasma is bounded away from zero, the dual black hole cannot be arbitrarily cold, but becomes unstable due to stringy instability once it reaches sufficiently low temperature. We study the stringy stability of flat dilaton black holes with dilaton coupling $\alpha=1$ in asymptotically anti-de Sitter space and show that unlike the purely electrically charged black hole, these dilaton black holes do not suffer from stringy instability.Comment: Published in Proceedings of the Conference in Honor of Murray Gell-Mann's 80th Birthday, p.583-590, World Scientific, 2010, Singapor

Hawking Evaporation Time Scale of Topological Black Holes in Anti-de Sitter Spacetime

It was recently pointed out that if an absorbing boundary condition is imposed at infinity, an asymptotically anti-de Sitter Schwarzschild black hole with a spherical horizon takes only a finite amount of time to evaporate away even if its initial mass is arbitrarily large. We show that this is a rather generic property in AdS spacetimes: regardless of their horizon topologies, neutral AdS black holes in general relativity take about the same amount of time to evaporate down to the same size of order L, the AdS length scale. Our discussion focuses on the case in which the black hole has toral event horizon. A brief comment is made on the hyperbolic case, i.e. for black holes with negatively curved horizons.Comment: Published versio

GUP-Corrected Black Hole Thermodynamics and the Maximum Force Conjecture

We show that thermodynamics for an asymptotically flat Schwarzschild black hole leads to a force of magnitude $c^4/(2G)$. This remains true if one considers the simplest form of correction due to the generalized uncertainty principle. We comment on the maximum force conjecture, the subtleties involved, as well as the discrepancies with previous results in the literature.Comment: Fixed a typo in Eq.(11) of the published versio

Charge Loss (or the Lack Thereof) for AdS Black Holes

The evolution of evaporating charged black holes is complicated to model in general, but is nevertheless important since the hints to the Information Loss Paradox and its recent firewall incarnation may lie in understanding more generic geometries than that of Schwarzschild spacetime. Fortunately, for sufficiently large asymptotically flat Reissner-Nordstrom black holes, the evaporation process can be modeled via a system of coupled linear ordinary differential equations, with charge loss rate governed by Schwinger pair-production process. The same model can be generalized to study the evaporation of AdS Reissner-Nordstrom black holes with flat horizon. It was recently found that such black holes always evolve towards extremality since charge loss is inefficient. This property is completely opposite to the asymptotically flat case in which the black hole eventually loses its charges and tends towards Schwarzschild limit. We clarify the underlying reason for this different behavior.Comment: References updated. Published in JHE

When Is Holography Consistent?

Holographic duality relates two radically different kinds of theory: one with gravity, one without. The very existence of such an equivalence imposes strong consistency conditions which are, in the nature of the case, hard to satisfy. Recently a particularly deep condition of this kind, relating the minimum of a probe brane action to a gravitational bulk action (in a Euclidean formulation), has been recognised; and the question arises as to the circumstances under which it, and its Lorentzian counterpart, are satisfied. We discuss the fact that there are physically interesting situations in which one or both versions might, in principle, \emph{not} be satisfied. These arise in two distinct circumstances: first, when the bulk is not an Einstein manifold, and, second, in the presence of angular momentum. Focusing on the application of holography to the quark-gluon plasma (of the various forms arising in the early Universe and in heavy-ion collisions), we find that these potential violations never actually occur. This suggests that the consistency condition is a "law of physics" expressing a particular aspect of holography.Comment: 26 pages, two diagram