Nonlinear elliptic systems

Abstract

In this paper we treat the question of the existence of solutions of boundary value problems for systems of nonlinear elliptic equations of the form - deltau = f (x, u, v,Ñu,Ñv), - deltav = g(x, u, v, Ñu, Ñv), in omega, We discuss several classes of such systems using both variational and topological methods. The notion of criticality takes into consideration the coupling, which plays important roles in both a priori estimates for the solutions and Palais-Smale conditions for the associated functional in the variational case.

Keywords

• elliptic equations
• variational methods
• palais-smale conditions
• leray-schauder degree
• a priori bounds