Speaker
Prof.
Rafael Torres
Description
A presentation of a group can be encoded into a link, i.e., a disjoint union of knots in the three-dimensional sphere. Such link contains enough information to (de)construct a four-dimensional smooth manifold. We'll sample this algorithm and give an overview of a proof of the following result.
Theorem (Dehn): Any finitely presented group is realised as the fundamental group of a closed smooth orientable 4-manifold.