Séminaire Algèbre Géométrie Algébrique Topologie Algébrique :

Le 05 novembre 2009 à 11:15 - salle 431

Présentée par Berrick Jon - National University of Singapore

Delta-structure on braid and mapping class groups of surfaces

The starting-point for this work (joint with E Hanbury and J Wu) is the theorem that elements of homotopy groups of spheres may be represented by Brunnian braids on the 2-sphere. Brunnian braids are those that become trivial when any one strand is removed. We consider what information is contained in Brunnian braid groups and Brunnian mapping class groups on other surfaces.