Abstract
Consider the nonlinear difference equations of the form L u = f m ( u )
, m ∈ Z , where L is a Jacobi operator given by L u m = a m u m + 1 + a
m − 1 u m − 1 + b m u m for m∈Z, { a m } and { b m } are real
valued T-periodic sequences, and f:Z×R→R. Applying
critical point theory and a new analytical method, we obtain that the
above problem has ground state solutions and infinitely many
geometrically distinct solutions under the local superlinear condition
lim | x | → ∞ ∫ 0 x f m ( t ) dt | x
| 2 = ∞ uniformly in m∈ D for some set D⊂Z
instead of the global superlinear condition lim | x |
→ ∞ ∫ 0 x f m ( t ) dt | x | 2 = ∞ uniformly in
m∈Z.