Resonant nonlinear periodic problems with the scalar $p$-Laplacian and a nonsmooth potential

Abstract

We study periodic problems driven by the scalar $p$-Laplacian with a nonsmooth potential. Using the nonsmooth critical point theory for locally Lipschitz functions, we prove two existence theorems under conditions of resonance at infinity with respect to the first two eigenvalues of the negative scalar $p$-Laplacian with periodic boundary conditions.