ABSTRACT
Various singularities in the superfluid He3 are considered: vortices, disgyrations, pointlike singularities, vortices with ends, singular surfaces, and particle-like states, as well as disclinations in cholestenc liquid crystals. A classification is presented of the topologically stable singularities. The methods of homotopic topology are used and are described with examples of well known systems such as superfluid He II, an isotropic ferromagnet, and a nematic liquid crystal. The possibility of applying these methods to ordinary crytals and to liquid crytals of the smectic type is discussed.
PACS numbers: 67.50.Fi, 61.30.–v
