BLACK-HOLE HORIZONS AND THE THERMODYNAMICS OF STRINGS

We review the classical thermodynamics and the greybody factors of gen eral (rotating) non-extreme black holes and discuss universal features of their near-horizon geometry. We motivate a microscopic interpretat ion of general black holes that relates the thermodynamics of an effec tive string theory to the geometry of the black hole in the vicinity o f both the outer and the inner event horizons. In this framework we in terpret several near-extreme examples, the universal low-energy absorp tion cross-section, and the emission of higher partial waves from gene ral black holes.