Key points are not available for this paper at this time.
The method of inverse spectral problems is applied for integrating the defocusing nonlinear Scrödinger (DNS) equation with loaded terms in the class of infinite-gap periodic functions. We describe the evolution of the spectral data for a periodic Dirac operator whose coefficient is a solution to the DNS equation with loaded terms. We prove the following assertions. (1) It the initial function is real-valued, -periodic, and analytic then the solution of the Cauchy problem for the DNS equation with loaded terms is a real-valued analytic function in x. (2) If 2 is the period (or antiperiod) of the initial function then 2 is the period (antiperiod) of the solution of the Cauchy problem problem with respect to x.
Muminov et al. (Tue,) studied this question.