The Nonlinear Schrodinger Equation on the Half Line
  The nonlinear Schrodinger equation on the half line with mixed boundary condition is investigated. After a brief introduction to the corresponding classical boundary value problem, the exact second quantized solution of the system is constructed. The construction is based on a new algebraic structure, which is called in what follows boundary algebra and which substitutes, in the presence of boundaries, the familiar Zamolodchikov-Faddeev algebra. The fundamental quantum field theory properties of the solution are established and discussed in detail. The relative scattering operator is derived in the Haag-Ruelle framework, suitably generalized to the case of broken translation invariance in space. 
M. Gattobigio (INFN, Pisa & Pisa U.), A. Liguori (ISAS, Trieste), M.   Mintchev (INFN, Pisa & Pisa U.)