Periodic soliton solutions to nonlinear Klein-Gordon equations on $\mathbb{R}^2$
Periodic soliton solutions to nonlinear Klein-Gordon equations on $\mathbb{R}^2$
In this paper, we prove the existence and the regularity of timeperiodic free vibrations to certain nonlinear Klein-Gordon equations in one space dimension.Those vibrations decay toward a constant equilibrium solution as the spatial variable goes to plus or minus infinity, and their spectrum consists of integral multiples of some prescribed …