Abstract: While topological ideas are widely popular in physics, topology of classical linear threads such as vortex lines in liquids or polymer chain molecules presents steep mathematical and conceptual challenges, with applications ranging from biopolymers to magnetohydrodynamics. After a historical introduction, I will start with the simplest phenomenon in the field: if you try to walk a dog on a (unreasonably) long leash, it is likely that the leash will soon be heavily wound around your legs. Viewing topological constraints as a form of quenched disorder, I will formulate a few known classical results about “knot entropy” and minimal thermodynamic work needed to untie all knots. Continuing with increasingly sophisticated models and phenomena, I will review several more recent theoretical and experimental achievements, and conclude with the discussion of a controversial concept of “topological glass”
Speaker Bio: Alexander Grosberg, Professor Of Physics, New York University, has been working on the theory of polymers and biopolymers ever since his Ph.D. and, later on, Doctor of Science on macromolecules under I M Lifshitz. He is currently associated with the Center for Soft Matter Research, Physics Department, NYU. Besides polymers, his significant contributions are in topological problems, nonequilibrium physics, and Biological problems like packaging and translocations of DNA.