Composite defect extends cosmology - 3He analogy
  Spin-mass vortices have been observed to form in rotating superfluid 3He-B following the absorption of a thermal neutron and a rapid transition from the normal to superfluid state. The spin-mass vortex is a composite defect which consists of a planar soliton (wall) which terminates on a linear core (string). This observation fits well within the framework of a cosmological scenario for defect formation, known as the Kibble-Zurek mechanism. It suggests that in the early Universe analogous cosmological defects might have formed. 
V.B. Eltsov, T.W.B. Kibble, M. Krusius, V.M.H. Ruutu, G.E. Volovik