Skew-self-adjoint Dirac systems with a rectangular matrix potential:   Weyl theory, direct and inverse problems
  A non-classical Weyl theory is developed for skew-self-adjoint Dirac systems with rectangular matrix potentials. The notion of the Weyl function is introduced and direct and inverse problems are solved. A Borg-Marchenko type uniqueness result and the evolution of the Weyl function for the corresponding focusing nonlinear Schr\"odinger equation are also derived. 
B. Fritzsche, B. Kirstein, I.Ya. Roitberg, A.L. Sakhnovich
math.CA math-ph math.MP math.SP nlin.SI