Topological and non-topological solitons of nonlinear Klein–Gordon equations by Heʹs semi-inverse variational principle

This paper studies the topological as well as the non-topological solitons due to the nonlinear Klein–Gordon equations, in presence of perturbation terms. There are five forms of nonlinearity that will be considered. The Heʹs semi-inverse variational principle will be used to carry out the integration.