BLACK-HOLE ENTROPY FROM NEAR-HORIZON MICROSTATES

Black holes whose near-horizon geometries are locally, but not necessa rily globally, AdS(3) (three-dimensional anti-de Sitter space) are con sidered. Using the fact that quantum gravity on AdS(3) is a conformal field theory, we microscopically compute the black hole entropy from t he asymptotic growth of states. Precise numerical agreement with the B ekenstein-Hawking area formula for the entropy is found. The result pe rtains to any consistent quantum theory of gravity, and does not use s tring theory or supersymmetry.