PAIR CREATION RATE FOR U(1)(2) BLACK-HOLES

I consider a truncation of low-energy string theory which contains two U(1) gauge fields. After making some general comments on the theory, I describe a previously obtained instanton for the pair creation of bl ack holes when both gauge fields are nonzero, and obtain the pair crea tion rate by calculating its action. This calculation agrees qualitati vely with the earlier calculation of the pair creation rate for black holes in Einstein-Maxwell theory. That is, the pair creation is strong ly suppressed in realizable circumstances, and it reduces to the Schwi nger result in the point-particle limit. The pair creation of nonextre me black holes is enhanced over that of extreme black holes by e(ABH/4 ).