title: Directed polymers with constrained winding angle.
abstract: In this paper we study from a nonperturbative point of view the entanglement of two directed polymers subjected to repulsive interactions given by a Dirac delta-function potential. An exact formula of the so-called second moment of the winding angle is derived. This result is used to provide a thorough analysis of entanglement phenomena in the classical system of two polymers subjected to repulsive interactions and related problems. No approximation is made in treating the constraint on the winding angle and the repulsive forces. In particular, we investigate how repulsive forces influence the entanglement degree of the two-polymer system. In the limit of ideal polymers, in which the interactions are switched off, we show that our results are in agreement with those of previous works.
authors.affiliation: Institute of Physics, University of Szczecin, ul. Wielkopolska 15, 70-451 Szczecin, Poland. ferrari@univ.szczecin.pl
authors.forename: Franco
authors.initials: F
authors.lastname: Ferrari
authors.forename: Vakhtang G
authors.initials: VG
authors.lastname: Rostiashvili
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Vilgis