A nonlinear eigenvalue problem for the periodic scalar p-Laplacian

We study a parametric nonlinear periodic problem driven by the scalar p-Laplacian. We show that if lambda^1 > 0 is the first eigenvalue of the periodicscalar p-Laplacian and lambda>lambda^1, then the problem has at least three nontrivial solutions one positive, one negative and the third nodal. Our approach is variational together with suitable truncation, perturbation and comparisontechniques.