The cubic nonlinear fractional Schr\"odinger equation on the half-line

TL;DR

This paper establishes local well-posedness and smoothing effects for the cubic nonlinear fractional Schrödinger equation on the half-line, extending known results from the full line to a half-line domain.

Contribution

It introduces a solution framework for the fractional Schrödinger equation on the half-line and proves near sharp local well-posedness results, including smoothing effects, using advanced harmonic analysis techniques.

Findings

Proved local well-posedness almost sharp with respect to known full-line results.

Demonstrated smoothing of solutions beyond initial data regularity.

Extended analysis to both focusing and defocusing nonlinearities.

Abstract

We study the cubic nonlinear fractional Schr\"odinger equation with L\'evy indices $\frac{4}{3}<\alpha< 2$ posed on the half-line. More precisely, we define the notion of a solution for this model and we obtain a result of local-well-posedness almost sharp with respect for known results on the full real line $\mathbb R$. Also, we prove for the same model that the solution of the nonlinear part is smoother than the initial data. To get our results we use the Colliander and Kenig approach based in the Riemann--Liouville fractional operator combined with Fourier restriction method of Bourgain \cite{Bourgain3} and some ideas of the recent work of Erdogan, Gurel and Tzirakis \cite{tzirakis2}. The method applies to both focusing and defocusing nonlinearities. As the consequence of our analysis we prove a smothing effect for the cubic nonlinear fractional Schr\"odinger equation posed in full line $\mathbb R$ for the case of the low regularity assumption, which was point out at the recent work \cite{tzirakis2}.