Multiplicity of Solutions for Schrödinger Equations with Concave-Convex Nonlinearities

We study the multiplicity of solutions for a class of semilinear Schrödinger equations: -Δu+V(x)u=gx,u, for x∈RN; u(x)→0, as u→∞, where V satisfies some kind of coercive condition and g involves concave-convex nonlinearities with indefinite signs. Our theorems contain some new nonlinearities