Special Session 15: Qualitative properties for solutions to nonlinear elliptic and parabolic equations

Uniqueness of entire solutions to quasilinear equations with a sub-natural growth term and measure data
Phuc C Nguyen
Louisiana State University
USA
Co-Author(s):    Igor E. Verbitsky
Abstract:
We present the uniqueness of nontrivial solutions to the problem \begin{equation*} \left\{ \begin{array}{ll} - \Delta_p u = \sigma u^q + \mu, \quad u\geq 0 \quad \text{in } \mathbb{R}^n, \ \displaystyle{\liminf_{|x|\rightarrow \infty}}\, u = 0, \end{array} \right. \end{equation*} in the sub-natural growth case $0\lt q\lt p-1$, where $\mu, \sigma$ are nonnegative locally finite measures in $\mathbb{R}^n$ absolutely continuous with respect to the $p$-capacity. Here $\Delta_p u:={\rm div}(|\nabla u|^{p-2}\nabla u)$, $1\lt p\lt \infty$, is the $p$-Laplace operator. The uniqueness is obtained in the class of \emph{reachable} solutions, and moreover, if the condition $\displaystyle{\liminf_{|x|\rightarrow \infty}}\, u = 0$ is replaced by the stronger condition $\displaystyle{\lim_{|x|\rightarrow \infty}}\, u = 0$, then such uniqueness is obtained in the larger class of $p$-superharmonic solutions. This talk is based on joint work with Igor E. Verbitsky.