On nonstationary inhomogeneities of the nonlinear Klein–Gordon equation

A system consisting of a point material particle and a field described by the nonlinear Klein–Gordon equation has been considered. The particle produces an inhomogeneity of the field and interacts with the field. It has been shown that this system including relativistic effects sometimes does not allow a stable energy minimum at zero velocity. Such a behavior is interesting for the construction of soliton models of particles with a nonzero characteristic angular momentum or soliton models of particles with an oscillation mass.