Concentration phenomena for a fractional Choquard equation with magnetic field

We consider the following nonlinear fractional Choquard equation epsilon(2s) (-Delta)(A/epsilon)(s) u + V(x)u = epsilon(mu-N) (1/vertical bar x vertical bar(mu) * F vertical bar mu vertical bar(2))) f(vertical bar u vertical bar(2))u in R-N, where epsilon > 0 is a parameter, s epsilon (0, 1), 0 < mu < 2s, N >= 3, (-Delta)(A) s is the fractional magnetic Laplacian, A : R-N -> R-N is a smooth magnetic potential, V : R-N -> R is a positive potential with a local minimum and f is a continuous nonlinearity with subcritical growth. By using variational methods we prove the existence and concentration of nontrivial solutions for epsilon > 0 small enough.