Seminar: Amenability; WS 2025/26

Prof. Dr. Clara Löh / Franziska Hofmann / Malena Wasmeier

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Please register on GRIPS if you want to participate in this seminar: GRIPS course for this seminar
Please select your preferences on GRIPS for talks by July 25, 2025. If you don't yet have access to GRIPS, you may send an email to malena.wasmeier@ur.de .
This seminar will be held in English. The written report can be in English or German. The handouts should be in English.

Seminar: Amenability

Amenability is a concept for groups, group actions or spaces that revolves around "almost-invariance". This concept can be characterised in many different settings and thus leads to rich interactions between group theory, geometry, dynamical systems, and functional analysis.

For instance, (non-)amenability plays a key role in the Banach--Tarski paradox: One can decompose the 3-ball into finitely many pieces that can be reassambled into two disjoint copies of the 3-ball of the same size. In this seminar, we will study various descriptions of amenable groups and actions, as well as classial applications of amenability. In particular, we will start with basics on infinite groups.

Time/Location

Wednesday, 8:30--10:00, M101

Material

Overview of all talks.
LaTeX template for handouts: .tex, .pdf
LaTeX template for reports: .tex, .pdf
Admin and preparation
Hints on writing mathematical texts (in German)
More such hints
Small print on slide talks

Prerequisites

Basic knowledge on groups, analysis, and topology (as done in Analysis I/II) is perfectly sufficient. It is sufficient to attend the Algebra course in parallel.

Formalities/Credits

See the commented list of courses.

Last Change: July 23, 2025.