A trace identity is proposed and it is shown that this identity can be effectively applied to establish the Hamiltonian structure of the KP, DS hierarchies and a new hierarchy of ( 1 -I-2)dimensional systems.1900

No abstract

No abstract

The sine-Gordon (SG) equation uxt = sin u arises from many branches of physics, and now is one of the most important equations in soliton theory. There have been many works concerning its soliton solutions, Backhand transformations, symmetries and conservation laws and other properties. In this paper we prove that every polynomial symmetry of the SG equation is Hamiltonian, that is, takes the form of D-l δh/δu.