Kinks in a non-linear massive sigma model
  We describe the kink solitary waves of a massive non-linear sigma model with an ${\mathbb S}^2$ sphere as the target manifold. Our solutions form a moduli space of non-relativistic solitary waves in the long wavelength limit of ferromagnetic linear spin chains. 
A. Alonso-Izquierdo, M. A. Gonzalez Leon, J. Mateos Guilarte