Space of kink solutions in SU(N)\times Z_2

Abstract

We find $(N+1)/2$ distinct classes (``generations'') of kink solutions in an $SU(N)\times Z_2$ field theory. The classes are labeled by an integer $q$. The members of one class of kinks will be globally stable while those of the other classes may be locally stable or unstable. The kink solutions in the $q^{th}$ class have a continuous degeneracy given by the manifold ${\Sigma }_q=H/K_q$, where $H$ is the unbroken symmetry group and $K_q$ is the group under which the kink solution remains invariant. The space ${\Sigma }_q$ is found to contain incontractable two spheres for some values of $q$, indicating the possible existence of certain incontractable spherical structures in three dimensions. We explicitly construct the three classes of kinks in an SU(5) model with quartic potential and discuss the extension of these ideas to magnetic monopole solutions in the model.

Comments: 11 pages, 3 figures. Several minor changes made. Matches the version accepted to PRD