Solitons, links and knots

Using numerical simulations of the full nonlinear equations of motion; we i nvestigate topological solitons of the Skyrme-Faddeev system, which is a mo dified O(3) sigma model in three space dimensions, in which the solitons ar e stabilized by the Hopf charge. We find that for solitons up to charge fiv e the solutions have the structure of closed strings, which become increasi ngly twisted as the charge increases. However. for higher charge the soluti ons are more exotic and comprise linked loops and knots. We discuss the str ucture and formation of these solitons and demonstrate that the key propert y responsible for producing such a rich variety of solitons is that of stri ng reconnection.