Invited Speaker
Enzo Orlandini
Interplay between writhe and knotting in swollen and compact lattice polygons.
It is known that polymer chains at equilibrium display strong correlations between writhe and knot distribution. This is true either in the swollen regimes or in situations in which the polymer is in a highly condensed state due, for example, to strong confinement. An important example is the abundance of chiral/torus knots found in DNA extracted from P4 bacteriophage that cannot be simulated by confinement alone but requires a writhe bias in the conformation sampling. Here we explore, by Monte Carlo simulations, the writhe/knotting relationship in a model of self-attracting N-edges polygons on the cubic lattice. By increasing the attraction between non consecutive neighbouring vertices the system undergo a transition from a swollen to a compact regime and the writhe/knotting relation can be discussed and compared in both regimes within the same framework. Work done in collaboration with Marco Baiesi and Stu Whittington