Continuous dependence of the Cauchy problem for the inhomogeneous nonlinear Schrödinger equation in $H^{s} (\mathbb R^{n} )$ (2107.00795v1)

Abstract: We consider the Cauchy problem for the inhomogeneous nonlinear Schr\"{o}dinger (INLS) equation [iu_{t} +\Delta u=|x|^{-b} f(u),\;u(0)\in H^{s} (\mathbb R^{n} ),] where $n\in \mathbb N$, $0<s<\min \{ n,\; 1+n/2\} $, $0<b<\min \{ 2,\;n-s,\;1+\frac{n-2s}{2} \} $ and $f(u)$ is a nonlinear function that behaves like $\lambda \left|u\right|^{\sigma } u$ with $\sigma\>0$ and $\lambda \in \mathbb C$. Recently, An--Kim \cite{AK21} proved the local existence of solutions in $H^{s}(\mathbb R^{n} )$ with $0\le s<\min { n,\; 1+n/2}$. However even though the solution is constructed by a fixed point technique, continuous dependence in the standard sense in $H^{s}(\mathbb R^{n} )$ with $0< s<\min { n,\; 1+n/2}$ doesn't follow from the contraction mapping argument. In this paper, we show that the solution depends continuously on the initial data in the standard sense in $H^{s}(\mathbb R^{n} )$, i.e. in the sense that the local solution flow is continuous $H^{s}(\mathbb R^{n} )\to H^{s}(\mathbb R^{n} )$, if $\sigma $ satisfies certain assumptions.