Semilinear elliptic equations with Hardy potential and subcritical source term

Phuoc-Tai Nguyen

Published 2015-10-13Version 1

Let $\Omega$ be a smooth bounded domain in $\mathbb{R}^N$ and $\delta(x)=\text{dist}\,(x,\partial \Omega)$. Assume $\mu>0$, $\nu$ is a nonnegative finite measure on $\partial \Omega$ and $g \in C(\Omega \times \mathbb{R}_+)$. We study positive solutions of $$ (P)\qquad -\Delta u - \frac{\mu}{\delta^2} u = g(x,u) \text{ in } \Omega, \qquad \text{tr}^*(u)=\nu. $$ Here $\text{tr}^*(u)$ denotes the \textit{normalized boundary trace} of $u$ which was recently introduced by M. Marcus and P. T. Nguyen. We focus on the case $0<\mu < C_H(\Omega)$ (the Hardy constant for $\Omega$) and provide some qualitative properties of solutions of (P). When $g(x,u)=u^q$ with $q>1$, we prove that there is a critical value $q^*$ (depending only on $N$, $\mu$) for (P) in the sense that if $1<q<q^*$ then (P) admits a solution under a smallness assumption on $\nu$, but if $q \geq q^*$ this problem admits no solution with isolated boundary singularity. Existence result is then extended to a more general setting where $g$ is \textit{subcritical}. We also investigate the case where the $g$ is linear or sublinear and give some existence results for (P).