Hopf Textures
  A Hopf texture is a vacuum field configuration of isovector fields which is an onto map from the space as a large three sphere to the vacuum manifold $S^2$. We construct a Hopf texture with spherically symmetric energy density and discuss the topological charge. A Hopf texture collapses, and we study the collapse process numerically. In our simulations, it is clear that a Hopf texture does not decay into a pair of monopoles. We also argue that the probability of forming Hopf textures in random processes is very small compared to that of global monopoles. 
Sun Hong Rhie and David P. Bennett