Knotted domain strings
  We construct meta-stable knotted domain strings on the surface of a soliton of the shape of a torus in 3+1 dimensions. We consider the simplest case of Z2 Wess-Zumino-type domain walls for which we can cover the torus with a domain string accompanied with an anti-domain string. In this theory, all (p,q)-torus knots can be realized as a linked pair of a(n) (un)knotted domain string and an anti-domain string. 
Minoru Eto and Sven Bjarke Gudnason
hep-th