Calculation of Second Topological Moment <m^2> of Two Entangled Polymers
  We set up a Chern-Simons theory for the entanglement of two polymers P_1 and P_2, and calculate the second topological moment <m^2>, where m is the linking number. The result applies approximately to a polymer in an ensemble of many others, if these are considered as a single very long effective polymer. 
F. Ferrari, H. Kleinert, I. Lazzizzera