Tee-Seminar der AG Kramer

Zeit und Ort:

Semester:		WS 2014
Zeit:		Di 10:30 - 11:30
Ort:		SR 1C

Inhalt:

Mitglieder der Arbeitsgruppe und Gäste tragen über ihre laufenden Forschungsarbeiten vor, oder über Themen, die uns interessieren. Vor dem Seminar (ab 10:00) gibt es in Zimmer 301b Tee.

Vorträge:

21.10.14 Rupert McCallum (Münster) Topological rigidity of totally disconnected locally compact groups

Abstract : There are two possible ways to prove that an absolutely quasi-simple algebraic group over a non-archimedean local field admits exactly one locally compact sigma-compact Hausdorff topology compatible with the group operations. One is by proving the result for all locally compact sigma-compact totally disconnected topological groups that are locally finitely generated and locally have finite abelianisation. Another way is by proving that closed Weyl transitive groups of automorphisms of a regular locally finite building have the topological rigidity property in question. We present both of these arguments.

20.11.14 Olga Varghese (Münster) Wirkungen von Aut(F_n) auf CAT(0) Räume, SR0, 12 Uhr.

25.11.14 Koen Struyve (Ghent) Free constructions for geometries of Coxeter type

Abstract :in 1981, Jacques Tits remarked that one can use free constructions to obtain geometries for Coxeter diagrams not containing any subdiagram of type A_3. This result however remained unpublished.
In this talk I will both give an introduction to this topic, and sketch a free construction for these geometries.