The first logic seminar of the new semester will be **today** Monday, January 23, from 4 to 5 in room 2866 East Hall.

Peter Krautzberger will speak on “Groups in beta(N)”.

Abstract:

Groups in (beta(N),+) are a messy business. The extension of addition is, globally speaking, far from being a group and, generally speaking, there’s very little knowledge about them.

I will discuss some of the known results on the known groups in beta(N) such as Zelenyuk’s Theorem on finite groups. The main goal of the talk is the proof that the maximal group of any minimal, idempotent ultrafilter contains the free group on 2^c-many generators.

Even though the talk is wrapping up the talks started last semester the proof is very self-contained.

This talk will be video recorded and available at vimeo.com/pkrautzberger.

There will also be a Google+ Hangout during the seminar via Peter Krautzberger.

Video of the talk and a partial write-up are now available here

Thanks!