Isotopies of links carried by Matsuda branched surfaces

Geometry Topology Seminar
Monday, August 16, 2010 - 2:00pm for 1 hour (actually 50 minutes)
Skiles 171
Bill Menasco – University of Buffalo
John Etnyre
We introduce two related sets of topological objects in the 3-sphere, namely a set of two-component exchangable links termed "iterated doubling pairs", and a see of associated branched surfaces called "Matsuda branched surfaces". Together these two sets possess a rich internal structure, and allow us to present two theorems that provide a new characterization of topological isotopy of braids, as well as a new characterization of transversal isotopy of braids in the 3-sphere endowed with the standard contact structure. This is joint work with Doug Lafountain, and builds upon previous seminal work of Hiroshi Matsuda.