Black Hole Horizons and the Thermodynamics of Strings *

Black holes as local horizons

This talk gives a brief introduction to black hole horizons and their role in black hole thermodynamics. In particular a distinction is made between quasilocally defined horizons and event horizons. Currently some new techniques have led to interesting developments and the field seems to be growing in two distinct directions. We will show how thermodynamics can equally well be applied to locall...

Black holes and black hole thermodynamics without event horizons

Dilaton black holes with squashed horizons and their thermodynamics

New charged solutions describing black holes with squashed horizons in 5D dilaton gravity are presented. The black hole spacetimes are asymptotically locally flat and have a spacial infinity R× S →֒ S. The solutions are analyzed and their thermodynamics is discussed by using the counterterm method.

Black holes without boundaries

We discuss some of the drawbacks of using event horizons to define black holes and suggest ways in which black holes can be described without event horizons, using trapping horizons. We show that these trapping horizons give rise to thermodynamic behavior and possibly Hawking radiation too. This raises the issue of whether the event horizon or the trapping horizon should be seen as the true bou...

Interface of General Relativity, Quantum Physics and Statistical Mechanics: Some Recent Developments

The arena normally used in black holes thermodynamics was recently generalized to incorporate a broad class of physically interesting situations. The key idea is to replace the notion of stationary event horizons by that of ‘isolated horizons.’ Unlike event horizons, isolated horizons can be located in a space-time quasi-locally. Furthermore, they need not be Killing horizons. In particular, a ...