Multiplicity of positive solutions for a nonlinear Schrödinger–Poisson system

In this paper, we study the multiplicity of positive solutions for a nonlinear Schrödinger–Poisson system:{−Δu+λu+K(x)ϕu=Q(x)|u|p−2u in R3,−Δϕ=K(x)u2 in R3, where λ>0λ>0, 2