Framed braids and homotopy groups of three-sphere
Organizers
Speaker
Vasilii Ionin
Time
Thursday, October 30, 2025 2:00 PM - 3:00 PM
Venue
A3-4-101
Online
Zoom 928 682 9093
(BIMSA)
Abstract
We discuss some fundamental connections between low-dimensional topology and homotopy theory. We give a new simple geometric proof of the Rimvydas Krasauskas' theorem computing the homotopy type of the simplicial group of framed surface braids. This suggests a simplicial model for the Lie group SU(2). Using this, we derive a well-known connection between Brunnian braids and homotopy groups of the 3-sphere, as explored by Fred Cohen, Jie Wu, and others.