The Polyakov Approach and Divergences in Open Superstrings

String theories have, recently re-emerged, pheonix-like, into the mainstream of particle physics. The principal reasons for this revival are threefold: Superstrings are believed to be renormalizable (possibly even finite), unitary, theories that include gravity as well as the usual gauge and matter interactions [1,2,30,33,34].Strings ‘miraculously’ satisfy very stringent requirements of mathematical consistency [2,3,4]. These requirements arise …