UNIVERSAL LOW-ENERGY DYNAMICS FOR ROTATING BLACK-HOLES

Fundamental string theory has been used to show that low-energy excita tions of certain black holes are described by a two-dimensional confor mal field theory. This picture has been found to be extremely robust. In this paper it is argued that many essential features of the low-ene rgy effective theory can be inferred directly from a semiclassical ana lysis of the general Kerr-Newman solution of supersymmetric four-dimen sional Einstein-Maxwell gravity, without using string theory. We consi der the absorption and emission of scalars with orbital angular moment um, which provide a sensitive probe of the black hole. We find that th e semiclassical emission rates-including super-radiant emission and gr eybody factors-for such scalars agree in striking detail with those co mputed in the effective conformal held theory, in both four and five d imensions. Also the value of the quantum mass gap to the lowest-lying excitation of a charge-Q black hole, E-gap = 1/8Q(3) in Planck units, can be derived without knowledge of fundamental string theory.