摘要：Multiple periodic solutions for the equation Δ ( p n ( Δ x n − 1 ) δ ) + q n x n δ = ∇ F ( n , x n ) , n ∈ Z , $$ \Delta \bigl(p_{n}(\Delta x_{n - 1})^{\delta } \bigr) + q_{n}x_{n}^{\delta } = \nabla F ( n,x_{n} ) , \quad n \in \mathbb{Z}, $$ are obtained via variational method and saddle-point theorem of Brezis and Nirenberg. Our main results extend some earlier results. An example is given.
