On stability of stationary soliton solutions to the nonlinear field equation in a general spinor model

The problem of determining the stability domain (in Lyapunov sense) of three dimensional soliton solutions is considered. Some necessary conditions for stability are obtained and it is shown that the boundary of the stability domain is defined by the inequality ωiωk(π{variant}Qi/π{variant}ωk < 0. © 1982.