“…If we assume some spectral properties, as doubly degenerate eigenspaces this theory allows to extend to field theories the classical Liouville theorem for the complete integrability of Hamiltonian dynamics, see [8,9,28,31]. Relaxing the conditions on the eigenspaces, the ideas behind Liouville integrability can be extended even to dissipative dynamics, [7]. There is a nice picture of the relation of the P-N structures on the manifold of potentials for the GZS system in canonical gauge, the manifold of potentials for the same system in pole gauge and the manifold of the corresponding Jost solutions, see [12,Chap.…”