Post-blowup dynamics for the nonlinear Schrödinger equation

Abstract

In this work, we present a systematic numerical study of the post-blowup dynamics of singular solutions of the 1D focusing critical NLS equation in the framework of a nonlinear damped perturbation. This study shows that initially, the post-blowup is described by the adiabatic approximation, in which the collapsing core approaches a universal profile and the solution width is governed by a system of ODEs (a reduced system). After that, a non-adiabatic regime is observed soon after the maximum of the solution, in which our direct numerical simulations show a clear deviation from the dynamics based on the reduced system. Our study suggests that such a non-adiabatic regime is caused by the increasing influx of mass into the collapsing core of the solution, which is not considered in the derivation of the reduced system. Also, adiabatic theoretical predictions related to the wave maximum and wave dissipation are compared with our numerical simulations. At the end of the post-collapse, the numerical simulations reveal a dominant quasi-linear regime caused by the rapid defocusing process. The collapsing core approaches the universal profile, after removing some oscillations resulting from interference with the tail. Finally, our numerical study suggests that in the limit of vanishing dissipation and, a free-space domain, the critical mass is radiated to infinity instantly at collapse time.