Multiple solutions for eigenvalue problems involving the (p, q)-Laplacian

This paper is devoted to a subject that Professor Csaba Varga suggested during his frequent visits to the University of Perugia and in my regular stays at the "Babes-Bolyai" University. More specifically, continuing the work started in [7] jointly with Professor Varga, here we establish the existence of two nontrivial (weak) solutions of some one parameter eigenvalue (p, q)-Laplacian problems under homogeneous Dirichlet boundary conditions in bounded domains of R-N.