Thermodynamic Metrics and Black Hole Physics

We give a brief survey of thermodynamic metrics, in particular the Hessian of the entropy function, and how they apply to black hole thermodynamics. We then provide a detailed discussion of the Gibbs surface of Kerr black holes. In particular we analyze its global properties, and extend it to take the entropy of the inner horizon into account. A brief discussion of Kerr-Newman black holes is included.Comment: 21 pages, new figures adde

Black Hole Physics from Liouville Theory

In a previous paper it was shown that the quantum consistency conditions for the dilaton-gravity theory of Callan et al., imply that the cosmological constant term undergoes a dilaton dependent renormalization, in such a manner that the theory can be written as a Liouville-like theory. In this paper we discuss the physical interpretation of the solutions of this theory. In particular we demonstrate explicitly how quantum corrections tame the black hole singularity. Also under the assumption that in asymptotically Minkowski coordinates, there are no incoming or outgoing ghosts, we show that the Hawking radiation rate is independent of the number of matter fields and is determined by the ghost conformal anomaly.Comment: 15 pages, phyzzx (Note on Bondi mass added to end of paper

Black Holes at the LHC: Progress since 2002

We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the `energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.Comment: 6 pages, 10 figures, Plenary talk given at the 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea (June 16-21, 2008). To be published in the Conference Proceeding

Non-Quasinormal Modes and Black Hole Physics

The near-horizon geometry of a large class of extremal and near-extremal black holes in string and M theory contains three-dimensional asymptotically anti-de Sitter space. Motivated by this structure, we are led naturally to a discrete set of complex frequencies defined in terms of the monodromy at the inner and outer horizons of the black hole. We show that the correspondence principle, whereby the real part of these ``non-quasinormal frequencies'' is identified with certain fundamental quanta, leads directly to the correct quantum behavior of the near-horizon Virasoro algebra, and thus the black hole entropy. Remarkably, for the rotating black hole in five dimensions we also reproduce the fractionization of conformal weights predicted in string theory.Comment: 4 pages, revtex4; v2: reference added; v3: more references, minor typo corrected; v4: minor rewording to adjust size (ugh!); v5: some small clarifications at referees' suggestio

4D quantum black hole physics from 2D models?

Minimally coupled 4D scalar fields in Schwarzschild space-time are considered. Dimensional reduction to 2D leads to a well known anomaly induced effective action, which we consider here in a local form with the introduction of auxiliary fields. Boundary conditions are imposed on them in order to select the appropriate quantum states (Boulware, Unruh annd Israel-Hartle-Hawking). The stress tensor is then calculated and its comparison with the expected 4D form turns out to be unsuccessful. We also critically discuss in some detail a recent controversial result appeared in the literature on the same topic.Comment: latex, 13 pages; misprints corrected, references adde

An effective Hamiltonian for 2D black hole Physics

In another application of the methods of Henneaux, Teitelboim, and Vergara developed for diffeomorphisms invariant models, the CGHS theory of 2D black holes is focused in order to obtain the true degrees of freedom, the simplectic structure and the {\it effective} Hamiltonian that rules the dynamics in reduced phase-space.Comment: To appear in Europhysics Letter

Edge states in Gravity and Black Hole Physics

We show in the context of Einstein gravity that the removal of a spatial region leads to the appearance of an infinite set of observables and their associated edge states localized at its boundary. Such a boundary occurs in certain approaches to the physics of black holes like the one based on the membrane paradigm. The edge states can contribute to black hole entropy in these models. A ``complementarity principle" is also shown to emerge whereby certain ``edge" observables are accessible only to certain observers. The physical significance of edge observables and their states is discussed using their similarities to the corresponding quantities in the quantum Hall effect. The coupling of the edge states to the bulk gravitational field is demonstrated in the context of (2+1) dimensional gravity.Comment: Revtex file, 22 pg. ( refs added , minor typos corrected

Varying Fine Structure Constant and Black Hole Physics

Recent astrophysical observations suggest that the value of fine structure constant $\alpha=e^2/\hbar c$ may be slowly increasing with time. This may be due to an increase of $e$ or a decrease of $c$, or both. In this article, we argue from model independent considerations that this variation should be considered adiabatic. Then, we examine in detail the consequences of such an adiabatic variation in the context of a specific model of quantized charged black holes. We find that the second law of black hole thermodynamics is obeyed, regardless of the origin of the variation, and that interesting constraints arise on the charge and mass of black holes. Finally, we estimate the work done on a black hole of mass $M$ due to the proposed $\alpha$ variation.Comment: 7 Pages, Revtex. Reference added, minor changes. Version to appear in Class. Quant. Gra