D-BRANE APPROACH TO BLACK-HOLE QUANTUM-MECHANICS

Strominger and Vafa have used D-brane technology to identify and preci sely count the degenerate quantum states responsible for the entropy o f certain extremal, BPS-saturated black holes. Here we give a Type-II D-brane description of a class of extremal and non-extremal five-dimen sional Reissner-Nordstrom solutions and identify a corresponding set o f degenerate D-brane configurations. We use this information to do a s tring theory calculation of the entropy, radiation rate and ''Hawking' ' temperature. The results agree perfectly with standard Hawking resul ts for the corresponding nearly extremal Reissner-Nordstrom black hole s. Although these calculations suffer from open-string strong coupling problems, we give some reasons to believe that they are nonetheless q ualitatively reliable. In this optimistic scenario there would be no ' 'information loss'' in black hole quantum evolution.