Existence and concentration of ground states for a Choquard equation with competing potentials

In this paper, we are concerned with the following Choquard equation in R3 that−ϵ2Δu+V(x)u=ϵμ−3[(∫R3P(y)|u(y)|p|x−y|μ)P(x)|u|p−2u+(∫R3Q(y)|u(y)|q|x−y|μ)Q(x)|u|q−2u], where ϵ>0 is a parameter, 0<μ<3, 6−μ3