Solitary waves in Galilean covariant Fermi field theories with   self-interaction
  The generalized Levy-Leblond equation for a $(3+1)$-dimensional self-interacting Fermi field is considered. Spin up solitary wave solutions with space oscillations in the $x^3$-coordinate are constructed. The solutions are shown to accumulate non-equal amounts of inertial and rest masses. 
Fuad M. Saradzhev
hep-th math-ph math.MP nlin.SI