Topology Seminar - Mariam Pirashvili Seminar

Event details

I will recall the classica notion of nonabelian cohomology of groups and talk about why there are only zero-th and first dimensional cohomology groups. This is a special case of the cohomotopy of cosimplicial groups, which are also only defined in the zero-th and first dimension in general. I introduce a new class of cosimplicial groups, called centralised cosimplicial groups, for which I was able to define a second cohomotopy, with all the expected properties. The main examples of such cosimplicial groups come from 2-categories.