We consider a nonlinear periodic problem driven by a nonhomogeneous differential operator, which includes as a particular case the scalar p-Laplacian. We assume that the reaction is a Carathéodory function which admits time-dependent zeros of constant sign. No growth control near ±∞ is imposed on the reaction. Using variational methods coupled with suitable truncation and comparison techniques, we prove two multiplicity theorems providing sign information for all the solutions.
Keywords: Constant sign solutions; Mountain pass theorem; Nodal solutions; Nonhomogeneous differential operator; Nonlinear strong maximum principle; Second deformation theorem.