2-DIMENSIONAL MINOR SYMMETRY FROM M-THEORY

We construct two-dimensional gauge theories with N = (4,4) supersymmet ry from branes of type IIA string theory. Quantum effects in the two-d imensional gauge theory are analyzed by embedding the IIA brane constr uction into M-theory. We find that the Coulomb branch of one theory an d the Higgs branch of a mirror theory become equivalent at strong coup ling. A relationship to the decoupling limit of the type IIA and IIB 5 -branes in Matrix theory is shown. T-duality between the ALE metric an d the wormhole metric of Callan, Harvey, and Strominger is discussed f rom a brane perspective and some puzzles regarding string duality reso lved, We comment on the existence of a quantum Higgs branch in two-dim ensional theories, Branes prove to be useful tools in analyzing singul ar conformal field theories. (C) 1998 Published by Elsevier Science B. V.