Existence and location of nodal solutions for quasilinear convection-absorption Neumann problems

Existence of nodal (i.e., sign changing) solutions and constant sign solutions for quasilinear elliptic equations involving convection-absorption terms are presented. A location principle for nodal solutions is obtained by means of constant sign solutions whose existence is also derived. The proof is chiefly based on sub-supersolutions technique together with monotone operator theory.