Well-posedeness for the non-isotropic Schr\"odinger equations on cylinders and periodic domains

TL;DR

This paper establishes local well-posedness results for the non-isotropic Schrödinger equation on cylinders and periodic domains in various Sobolev spaces, and discusses ill-posedness in certain cases, advancing understanding of these equations' behavior.

Contribution

It provides new well-posedness results for the non-isotropic Schrödinger equation on cylinders and tori, including specific Sobolev space conditions, and analyzes ill-posedness in the focusing case.

Findings

Well-posedness for small initial data in $H^s$ with $s\\geq0$ on cylinders.

Local well-posedness in anisotropic Sobolev spaces for data in $H^{s_1,s_2}$ with $s_1\\geq0$, $s_2>\frac12$.

Ill-posedness in the focusing case for $s$ in $[-\frac12,0)$ on $\\mathbb{T} \\times \\mathbb{R}$.

Abstract

The initial value problem (IVP) for the non-isotropic Schr\"odinger equation posed on the two-dimensional cylinders and $\mathbb{T}^2$ is considered. The IVP is shown to be locally well-posed for small initial data in $H^s(\mathbb{T}\times\mathbb{R})$ if $s\geq0$. For the IVP posed on $\mathbb{R}\times\mathbb{T}$, given data are considered in the anisotropic Sobolev spaces thereby obtaining the local well-posedness result in $H^{s_1, s_2}(\mathbb{R}\times\mathbb{T})$, if $s_1\geq0$ and $s_2>\frac12$. In the purely periodic case, a particular case of the IVP is shown to be locally well-posed for any given initial data in $H^s(\mathbb{T}^2)$ if $s>\frac14$. In some cases, ill-posedness issues are also considered showing that the IVP posed on $\mathbb{T}\times \mathbb{R}$, in the focusing case, is ill-posed in the sense that the application data-solution fails to be uniformly continuous for data in $H^s(\mathbb{T}\times\mathbb{R})$ if $-\frac12\leq s<0$.