Existence of positive ground state solutions of critical nonlinear Klein-Gordon-Maxwell systems

In this paper we study the following nonlinear Klein-Gordon-Maxwell system { -delta u + [m(0)(2 )- (omega + phi)(2)]u = f (u) in R-3, delta phi = (omega + phi)u in R-3, where 0 < omega < m(0). Based on an abstract critical point theorem established by Jeanjean, the existence of positive ground state solutions is proved, when the nonlinear term f(u) exhibits linear near zero and a general critical growth near infinity. Compared with other recent literature, some different arguments have been introduced and some results are extended.