Existence of solutions for perturbed fractional p-Laplacian equations

The purpose of this paper is to investigate the existence of weak solutions for a perturbed nonlinear elliptic equation driven by the fractional p-Laplacian operator as follows:(−Δ)psu+V(x)|u|p−2u=λa(x)|u|r−2u−b(x)|u|q−2uin RN, where λ   is a real parameter, (−Δ)ps is the fractional p  -Laplacian operator with 0