Asymptotic Stability of multi-solitons for $1$d Supercritical NLS
Gong Chen, Abdon Moutinho
TL;DR
This work proves the asymptotic stability of multi-solitons for the 1D $L^{2}$-supercritical NLS $i\partial_t\psi+\partial_x^2\psi+|\psi|^{2k}\psi=0$ with $k>2$ on a finite-codimension center-stable manifold, extending Krieger–Schlag’s single-soliton results to multi-solitons under a well-separated, nondegenerate spectral framework. The authors develop and leverage a linear theory for one-dimensional matrix charge transfer models to obtain dispersive and weighted estimates for the linearized flow around moving solitons, then implement a finite-time iterative contraction scheme that terminates unstable modes and passes to a limit. They construct a modulated multi-soliton decomposition plus a radiative component, proving precise decay and scattering properties for the remainder and establishing a center-stable manifold of codimension $m$ (and, via a more detailed analysis, a codimension-$m$ manifold on the soliton family). The results hinge on a careful spectral analysis of the linearized operators, sharp dispersive estimates for multi-potential configurations, and a robust nonlinear control strategy that accommodates slow soliton-soliton interactions in one dimension. This advances understanding of soliton resolution in 1D non-integrable settings and demonstrates asymptotic stability for more complex multi-soliton configurations than previously known.
Abstract
Consider the one-dimensional $L^2$ supercritical nonlinear Schrödinger equation \begin{equation} i\partial_{t}ψ+\partial^{2}_{x}ψ+\vert ψ\vert^{2k}ψ=0 \text{, $k>2$}. \end{equation} It is well known that solitary waves for this equation are unstable. In the pioneering work of Krieger and Schlag \cite{KriegerSchlag}, the asymptotic stability of a solitary wave was established on a codimension-one center-stable manifold. In the present paper, using linear estimates developed for one-dimensional matrix charge transfer models in our previous work, \cite{dispanalysis1}, we prove asymptotic stability of multi-solitons on a finite-codimension manifold for $k>\frac{11}{4}.$
