BPS Black Holes 3 M -

Classical black holes are solutions of Einstein’s equations of general relativity that exhibit an event horizon. From inside this horizon, nothing (and in particular, no light) can escape. The region inside the horizon is therefore not in the backward lightcone of future timelike infinity. However, since the discovery of Hawking radiation [1], it has become clear that many of the classical features of black holes will be subject to change. In these lecture we consider static, spherically symmetric black holes in four space-time dimensions that carry electric and/or magnetic charges with a flat space-time geometry at spatial infinity. Such solutions exist in Einstein-Maxwell theory, the classical field theory of gravity and electromagnetism. The most general static black holes of this type correspond to the ReissnerNordstrom solutions and are characterized by a charge Q and a mass M . In the presence of magnetic charges, Q is replaced by √