%0 Journal Article %T Microscopic- versus Effective Coupling in N=2 Yang-Mills With Four Flavours %A Ivo Sachs %A William Weir %J Physics %D 1999 %I arXiv %R 10.1016/S0370-2693(00)00338-5 %X We determine the instanton corrections to the effective coupling in SU(2), N=2 Yang-Mills theory with four flavours to all orders. Our analysis uses the S(2,Z)-invariant curve and the two instanton contribution obtained earlier to fix the higher order contributions uniquely. %U http://arxiv.org/abs/hep-th/9910015v3