Fermionic String from Abelian Higgs Model with monopoles and   $\Theta$-term
  The four dimensional Abelian Higgs model with monopoles and $\Theta$-term is considered in the limit of the large mass of the higgs boson. We show that for $\Theta=2 \pi$ the theory is equivalent, at large distances, to summation over all possible world-sheets of fermionic strings with Dirichlet type boundary conditions on string coordinates. 
E.T. Akhmedov (ITEP)