Mode stability for self-similar blowup of slightly supercritical NLS: II. high-energy spectrum

TL;DR

This paper proves the high-energy mode stability of self-similar blowup solutions in slightly supercritical nonlinear Schrödinger equations across dimensions 1 to 10, confirming asymptotic stability and characterizing the spectrum of the linearized operator.

Contribution

It establishes the high-energy mode stability for self-similar blowup in slightly supercritical NLS and characterizes the spectrum around the ground state, extending previous results.

Findings

Confirmed asymptotic stability of self-similar blowup

Characterized spectrum for linearized operator around ground state

Validated stability analysis with numerical methods

Abstract

In continuation of the study of the companion work, we prove the high-energy mode stability for linearized operator around self-similar profiles in [Bahri-Martel-Rapha\"el, 2021] for slightly mass-supercritical NLS in $1 \le d \le 10$. This concludes the asymptotic stability of such self-similar blowup, and answers the question from [Bahri-Martel-Rapha\"el, 2021] and [Merle-Rapha\"el-Szeftel, 2010]. As a byproduct, we characterize the spectrum for linearized operator around mass-critical ground state for $1 \le d \le 10$, which could be useful for future studies of asymptotic behavior near ground state. The core idea is a linear Liouville argument, originated by Martel-Merle [Martel-Merle, 2000, 2001] studying soliton stability, to reformulate the eigen problem as rigidity of linear dynamics so as to introduce modulation and to apply nonlinear dynamical controls. Our controlling quantities were verified with numerical help in [Merle-Rapha\"el, 2005; Fibich-Merle-Rapha\"el, 2006; Yang-Roudenko-Zhao, 2018] for $1 \le d \le 10$.