2-DIMENSIONAL INTEGRABLE SYSTEMS AND SELF-DUAL YANG-MILLS EQUATIONS

The relation between two-dimensional integrable systems and four-dimen sional self-dual Yang-Mills equations is considered. Within the twisto r description and the zero-curvature representation a method is given to associate self-dual Yang-Mills connections with integrable systems of the Korteweg-de Vries and nonlinear Schrodinger type or principal c hiral models. Examples of self-dual connections are constructed that a s points in the moduli do not have two independent conformal symmetrie s.