"The fundamental crossed module of the complement of a knotted surface in the 4-sphere"Joao Faria Martins (Leeds)

After a review on homotopy 2-types and crossed modules, I will show a method to calculate the homotopy 2-type of the complement of a knotted surface in the 4-sphere given a movie presentation of it. We therefore generalise Wirtinger relations for the fundamental group of a knot complement. [1] Faria Martins J.: The Fundamental Crossed Module of the Complement of a Knotted Surface. Transactions of the American Mathematical Society. 361 (2009), 4593-4630. [2] Faria Martins J., Kauffman L.H.: Invariants of Welded Virtual Knots Via Crossed Module Invariants of Knotted Surfaces, Compositio Mathematica. 144:04 (2008) 1046-1080.

Event details


May 02, 2017
from 02:00 PM to 03:00 PM


MA 119

Add event to calendar

Share this page:

Contact details

Department of Mathematics
University of Leicester
University Road
Leicester LE1 7RH
United Kingdom

Tel.: +44 (0)116 229 7407

Campus Based Courses

Undergraduate: mathsug@le.ac.uk
Postgraduate Taught: mathspg@le.ac.uk

Postgraduate Research: pgrmaths@le.ac.uk

Distance Learning Course  

Actuarial Science:

DL Study

Student complaints procedure

AccessAble logo

The University of Leicester is committed to equal access to our facilities. DisabledGo has detailed accessibility guides for College House and the Michael Atiyah Building.