How quantum theory and statistical mechanics gave a polynomial of knots
We will see how a result in von Neumann algebras (a theory developed by von Neumann to give the mathematical framework for quantum physics) gave rise, rather serendipitously, to an elementary but very useful invariant in the theory of ordinary knots in three dimensional space. Then we'll look at some subsequentÂ developments of the theory, and talk about a thorny problem which remains open.