Multiplicity results for a Neumann problem involving the p-Laplacian

In this paper, we establish some multiplicity results for the following Neumann problem \begin{center} \[\left \{ \begin{array}{ll} -div(\mid\nabla u\mid^{p-2}\nabla u)+ \lambda(x)\mid u \mid^{p-2}u= \alpha(x)f(u) & \mbox{ in $\Omega$ } \\ \partial u/\partial \nu=0 & \mbox{ on $\partial\Omega$}. \end{array} \right. \] \end{center} The multiple solutions are obtained by combining an existence theorem recently proved by G.Anello and G.Cordaro with well known critical point theorems.