NEW INTEGRABLE EXTENSIONS OF N=2 KDV AND BOUSSINESQ HIERARCHIES

We construct a new variety of N = 2 supersymmetric integrable systems by the junction of pseudo-differential superspace Lax operators for a = 4, N = 2 KdV and multi-component N = 2 NLS hierarchies. As an import ant special case, we obtain the Lax operator for the N = 4 super KdV s ystem. A similar extension of one of the N = 2 super Boussinesq hierar chies is given. We also present a minimal N = 4 supersymmetric extensi on of the second flow of the N = 4 KdV hierarchy, and comment on its p ossible integrability. (C) 1997 Published by Elsevier Science B.V.