A KIND OF NEW CONTINUOUS LIMITS OF AN INTEGRABLE COUPLING SYSTEM FOR DISCRETE AKNS HIERARCHY

Abstract

We present a kind of new continuous limits of an integrable coupling system for discrete AKNS hierarchy by using of Lie algebra sl(4). By introducing a complex discrete spectral problem, a coupling lattice hierarchy is derived. It is shown that a new sequence of combinations of complex lattice spectral problem converges to the integrable couplings of soliton equation hierarchy, which has the integrable coupling system of AKNS hierarchy as a continuous limit.