(p, q)-Equations with Negative Concave Terms

Abstract

In this paper, we study a nonlinear Dirichlet problem driven by the (p, q)-Laplacian and with a reaction that has the combined effects of a negative concave term and of an asymmetric perturbation which is superlinear on the positive semiaxis and resonant in the negative one. We prove a multiplicity theorem for such problems obtaining three nontrivial solutions, all with sign information. Furthermore, under a local symmetry condition, we prove the existence of a whole sequence of sign-changing solutions converging to zero in C^1_0(overline{Omega }).