Periodic and subharmonic solutions for 2nnth-order ϕcϕc-Laplacian difference equations containing both advance and retardation

In this paper, a 2nnth-order ϕcϕc-Laplacian difference equation is considered. By using the critical point theory, we establish some new criteria for the existence and multiplicity of periodic and subharmonic solutions. The proof is based on the Linking Theorem in combination with variational technique.