Zy. Chen et Nn. Huang, HAMILTONIAN-FORMALISM FOR THE NLS EQUATION WITH NONVANISHING BOUNDARY-CONDITION, Communications in Theoretical Physics, 22(2), 1994, pp. 173-182
For the NLS equation with nonvanishing boundary condition, Hamiltonian
formalism is developed. Together with two previous works, the results
obtained are in the same level as those obtained for the NLS equation
with vanishing boundary condition.