I’m going to abuse this here organ of mine to show off a thing I did yesterday.

My chum the inimitable David Cushing has started a postgrad pure maths seminar at Newcastle. Because there are only a few pure postgrads here, he asked me to give a talk about the stuff I was looking at for the PhD I gave up on last year.

The title of the talk was “Computability of Bass-Serre structures in the Grzegorczyk hierarchy”. It gave an outline of everything needed to show that the fundamental group of a graph of groups is computable in a level of the Grzegorczyk hierarchy at most one higher than its constituent parts, and what that means.

The slides, a recording of the talk, and a link to my presentation template are in a post on my mathem-o-blog: Talk: Computability of Bass-Serre structures in the Grzegorczyk hierarchy