M. Desaix et al., VARIATIONALLY OBTAINED APPROXIMATE EIGENVALUES OF THE ZAKHAROV-SHABATSCATTERING PROBLEM FOR REAL POTENTIALS, Physics letters. A, 212(6), 1996, pp. 332-338
A variational procedure, based on trial functions, for finding approxi
mate eigenvalues of the Zakharov-Shabat eigenvalue problem for real po
tentials is presented.