SOLUTIONS OF 4-DIMENSIONAL FIELD-THEORIES VIA M-THEORY

N = 2 supersymmetric gauge theories in four dimensions are studied by formulating them as the quantum field theories derived from configurat ions of fourbranes, fivebranes, and sixbranes in Type ITA superstrings , and then reinterpreting those configurations in M-theory. This appro ach leads to explicit solutions for the Coulomb branch of a large fami ly of four-dimensional N = 2 field theories with zero or negative beta function. (C) 1997 Elsevier Science B.V.