Integrable couplings of vector AKNS soliton equations

By enlarging the associated matrix spectral problems, two specific classes of multicomponent integrable couplings of the physically important vector AKNS soliton equations are constructed, which can be linked to each other by a Backlund transformation. The resulting two hierarchies of integrable couplings possess the enlarged zero curvature representations and recursion structures, and thus each system in the two hierarchies has infinitely many commuting symmetries. (C) 2005 American Institute of Physics.