06.12.2022

Holger Kammeyer (Heinrich Heine University Düsseldorf)

Title

Galois cohomology and absolutely solitary groups

Abstract

If two arithmetic groups have the same set of finite quotients, are  they necessarily isomorphic or at least commensurable?  We construct examples and non-examples by Galois cohomological methods.  In addition, we discuss how recent progress in the field brings us close to the construction of "absolutely solitary" arithmetic groups, meaning the commensurability class of the profinite completion determines the arithmetic group up to commensurability among residually finite groups.

Schedule

10:00 - 11:30 RTG Lecture 1 (Wilderich Tuschmann), SR 2.058

11:30 - 12:00 Get-Together with speaker, SR 2.058

12:00 - 13:00 Common lunch

13:00 - 13:30 Informal meeting of PhD students, room 1.062

13:45 - 14:45 RTG colloquium: Holger Kammeyer, SR. 1067

14:45 - 15:30 Common tea, Faculty meeting room 1.058

15:30 - 17:00 RTG Lecture 2 (Wilderich Tuschmann), SR 1.067

KA