Finite many critical problems involving Fractional Laplacians in ${\mathbb{R}}^N$

In this paper, we consider the nonlocal elliptic problems in ${\mathbb{R}}^N$, which involve finite many critical exponents. By using endpoint refined Hardy–Sobolev inequality, fractional Coulomb–Sobolev space and variational method, we establish the existence of nonnegative solution. Our results generalize some results obtained by Yang and Wu [Adv. Nonlinear Stud. (2017) \cite{Yang2017}].