Periodic travelling wave solutions of discrete nonlinear Klein-Gordon lattices
arXiv:2212.05575 · doi:10.1002/mma.9566
Abstract
We prove the existence of periodic travelling wave solutions for general discrete nonlinear Klein-Gordon systems, considering both cases of hard and soft on-site potentials. In the case of hard on-site potentials we implement a fixed point theory approach, combining Schauder's fixed point theorem and the contraction mapping principle. This approach enables us to identify a ring in the energy space for non-trivial solutions to exist, energy (norm) thresholds for their existence and upper bounds on their velocity. In the case of soft on-site potentials, the proof of existence of periodic travelling wave solutions is facilitated by a variational approach based on the Mountain Pass Theorem. Thresholds on the averaged kinetic energy for these solutions to exist are also derived.
17 pages, 1 figure. To appear in Mathematical Methods in the Appled Sciences