ON TOPOLOGICAL EXCITATIONS WITH ISOVECTOR TOPOLOGICAL CHARGES

It is shown that degenerate systems with order parameter psi taking on values in compact homogeneous subspaces T-G or G/T-G (where G is a si mple compact group and T-G is its maximum commutative subgroup) posses s a rich collection of topological excitations (vortices or, correspon dingly, instantons) with isovector topological charges. The correspond ing homotopy groups are found for all G. The possibility of a topologi cal interpretation of the quantum numbers of the groups and particles is discussed. (C) 1996 American Institute of Physics.