Pairs of positive radial solutions for a Minkowski-curvature Neumann problem with indefinite weight

Abstract

We prove the existence of a pair of positive radial solutions for the Neumann boundary value problem \begin{equation*} \begin{cases} \, \mathrm{div}\,\Biggl{(} \dfrac{\nabla u}{\sqrt{1- | \nabla u |^{2}}}\Biggr{)} + λa(|x|)u^p = 0, & \text{in $B$,} \\ \, \partial_νu=0, & \text{on $\partial B$,} \end{cases} \end{equation*} where $B$ is a ball centered at the origin, $a(|x|)$ is a radial sign-changing function with ${\int }_{B}a(|x|)\mathrm{d}x<0$, $p>1$ and $\lambda >0$ is a large parameter. The proof is based on the Leray-Schauder degree theory and extends to a larger class of nonlinearities.

17 pages, 4 PDF figures