Introducing a Relativistic Nonlinear Field System With a Single Stable Non-Topological Soliton Solution in 1+1 Dimensions

In this paper we present a new extended complex nonlinear Klein-Gordon Lagrangian density, which bears a single non-topological soliton solution with a specific rest frequency $\omega_{s}$ in $1+1$ dimensions. There is a proper term in the new Lagrangian density, which behaves like a massless spook that surrounds the single soliton solution and opposes any internal changes. In other words, any arbitrary variation in the single soliton solution leads to an increase in the total energy. Moreover, just for the single soliton solution, the general dynamical equations are reduced to those versions of a special type of the standard well-known complex nonlinear Klein-Gordon systems, as its dominant dynamical equations.