SESZIONE DI TORINO
I will review the construction of BPS solutions that describe black rings as well as "black hole microstates" - smooth horizonless solutions that have the same charges and the same angular momenta as three-charge 5D BPS black holes and black rings. I will then describe the connection between these solutions and the 4D multi-center black hole solutions that have been extensively studied by Denef and Moore. In the last part I will discuss some of the properties of these solutions that indicate that they describe typical black hole microstates in the same regime of parameters where the classical black hole solution exists. If this is indeed the case, then string theory would imply that a classical black hole solution is only a thermodynamic approximation of an ensemble of horizonless configurations, which stops giving a valid description of the physics at the scale of the horizon.

DATA: 04-03-2008