Energy scattering for the unsteady damped nonlinear Schrodinger equation
Makram Hamouda, Mohamed Majdoub
TL;DR
This work analyzes the long-time dynamics of the focusing nonlinear Schrödinger equation with time-dependent damping in the energy-subcritical to intercritical range. It develops a damping-augmented framework, including the transform $v=e^{\mathbf A(t)}u$ and energy identities, together with Strichartz estimates and Grönwall-type bootstraps to establish uniform $H^1$ control and scattering. The main contributions are: (i) $H^1$-scattering for $1<p\le 1+\frac{4}{N}$ under $\underline{\mathbf a}>0$ (Theorem scat1); (ii) global existence and scattering for $1+\frac{4}{N}<p<1+\frac{4}{(N-2)_+}$ under a small-damped-Strichartz condition, plus a conditional result when $\sup_{t\ge0}\|u(t)\|_{L^{p+1}}<\infty$; and (iii) a scattering result under an exponential decay bound on the gradient (Theorem scat3-bis). The results extend constant-damping scattering theory to time-dependent damping and clarify how damping strength interacts with initial data to yield global behavior. Open questions include scattering with $\underline{\mathbf a}=0$ and extensions to slowly decaying damping and energy-critical regimes.
Abstract
We investigate the large time behavior of the solutions to the nonlinear focusing Schrödinger equation with a time-dependent damping in the energy sub-critical regime. Under non classical assumptions on the unsteady damping term, we prove some scattering results in the energy space.
