Multiple positive solutions for a Schr?dinger-Poisson-Slater equation with critical growth

We consider the multiplicity of positive solutions for a Schrodinger-Poisson-Slater equation of the type where mu > 0, 3 < p < 5, and g E C(R3,R+). Using Ekeland's variational principle and the well-known arguments of the concentration-compactness principle of Lions (1984) [24,25], when g has one local maximum point, we obtain a positive ground -state solution for all mu > 0, while for g with k strict local maximum points, we prove that the equation has at least k distinct positive solutions for mu > 0 small. The uses a minimization on the Nehari manifold.