On the existence of solutions for nonhomogeneous Schrodinger-Poisson system

In this paper, we study the existence of solutions for the following nonhomogeneous Schrodinger-Poisson systems: (*) {-Delta u + V(x) u + K(x)phi(x) u = f (x, u) + g(x), x is an element of R-3, -Delta phi = K(x) u(2), lim(vertical bar x vertical bar ->+infinity)phi(x) = 0, x is an element of R-3, where f (x, u) is either sublinear in u as vertical bar u vertical bar ->infinity or a combination of concave and convex terms. Under some suitable assumptions, the existence of solutions is proved by using critical point theory.