We consider a class of discrete nonlinear Schrdinger equations with unbounded potentials. We obtain some new multiplicity results of breathers of the equations by using critical point theory. Our results greatly improve some recent results in the literature.
In this paper, we consider the existence of homoclinic solutions in periodic nonlinear difference equations with superlinear nonlinearity. The classical Ambrosetti–Rabinowitz superlinear condition is improved by a general superlinear one. The proof is based on the critical point theory in combination with periodic approximations of solutions.
