The main advantage of a homology theory with respect to its Euler characteristic is its functoriality, i.e. maps between spaces induce maps between homology groups. Khovanov homology associates homology groups with links and maps between them with link cobordisms. However, this theory is only projectively functorial, i.e. the sign of the map induced by a link cobordism depend on its pair of pants decomposition. Even this weak functorial behaviour led to a new proof of the Milnor conjecture computing the slice genus of torus knots by Rasmussen. In the talk after a gentle introduction to Khovanov homology I will explain how to fix the sign issue.
Donnerstag, den 17. Oktober 2019 um 17.15 Uhr, in INF 205, HS Mathematikon Donnerstag, den 17. Oktober 2019 at 17.15, in INF 205, HS Mathematikon
Der Vortrag folgt der Einladung von The lecture takes place at invitation by Prof. Dr. G. Böckle