Multiplicity results for a nonlinear elliptic problem involving the fractional laplacian

In this paper, we consider a class of superlinear elliptic problems involving fractional Laplacian (−Δ)s/2u = δf (u) in a bounded smooth domain with zero Dirichlet boundary condition. We use the method on harmonic extension to study the dependence of the number of sign-changing solutions on the parameter A.