Regularization by noise for the energy- and mass-critical nonlinear Schrödinger equations
Martin Spitz, Deng Zhang, Zhenqi Zhao
TL;DR
The paper addresses the challenge of blow-up and non-scattering in the focusing energy- and mass-critical stochastic NLS by introducing non-conservative multiplicative noise. It converts the SNLS to a random NLS via a Doss–Sussmann-type transform $u(t)=e^{\hat{\mu}t-W(t)}X(t)$ with $W(t)=\sum_k \phi_k\beta_k(t)$ and a geometric Brownian factor $h_c$, proving a pivotal decay estimate for $h_c$ after time $\|c\|^{-1}$. Using a two-step construction that separates a short-time dispersive regime from a long-time regime, the authors obtain global existence and forward scattering with probability tending to 1 as $\|c\|\to\infty$ in both the energy- and mass-critical cases. This establishes a robust regularization-by-noise phenomenon for critical dispersive SPDEs, extending prior subcritical results and highlighting the potential of noise to suppress singular behavior in focusing NLS.
Abstract
In this article we prove a regularization by noise phenomenon for the energy-critical and mass-critical nonlinear Schrödinger equations. We show that for any deterministic data, the probability that the corresponding solution exists globally and scatters goes to one as the strength of the non-conservative noise goes to infinity. The proof relies on the rescaling transform and a new observation on the rapid uniform decay of geometric Brownian motions after short time.
