On the Landis conjecture for the fractional Schrödinger equation

Abstract

In this paper, we study a Landis-type conjecture for the general fractional Schrödinger equation $((-P)^{s}+q)u=0$. As a byproduct, we also prove the additivity and boundedness of the linear operator $(-P)^{s}$ for non-smooth coefficents. For differentiable potentials $q$, if a solution decays at a rate $\exp(-|x|^{1+})$, then the solution vanishes identically. For non-differentiable potentials $q$, if a solution decays at a rate $\exp(-|x|^{\frac{4s}{4s-1}+})$, then the solution must again be trivial. The proof relies on delicate Carleman estimates. This study is an extension of the work by Rüland and Wang (2019).