Large scale limit for a dispersion-managed NLS
Jason Murphy
TL;DR
This work establishes a rigorous large-scale limit connecting the Gabitov--Turitsyn dispersion-managed NLS to the standard power-type NLS in the defocusing, two-dimensional cubic regime. By scaling the NLS solution and exploiting a bespoke stability theory for DMNLS built on shifted Strichartz estimates, the authors show that DMNLS solutions with suitably large spatial scales approximate NLS solutions, and vice versa in the small-dispersion limit. The main result proves that for any initial data in $L^2$, there exist global, scattering DMNLS solutions at sufficiently small scaling parameter, and that these DMNLS solutions converge to the corresponding scaled NLS solutions in both the $L_t^{\infty}L_x^2$ and spacetime $L_{t,x}^4$ norms. Consequently, the DMNLS model admits global, scattering solutions of arbitrarily large $L^2$-norm, linking averaging phenomena in dispersion management to classical NLS dynamics and enabling insights into both large- and small-scale limits.
Abstract
We derive the standard power-type NLS as a scaling limit of the Gabitov--Turitsyn dispersion-managed NLS, using the $2d$ defocusing, cubic equation as a model case. In particular, we obtain global-in-time scattering solutions to the dispersion-managed NLS for large scale data of arbitrary $L^2$-norm.
