© MM/Lehmann

Focus Programme

Actions of totally disconnected locally compact groups on discrete structures

September - October 2023

This focus programme aims to foster collaborations in the study of locally compact groups acting on infinite discrete structures such as graphs and buildings. Key themes include geometric and combinatorial approaches, local-to-global phenomena, self-similarity and topological dynamics. We encourage participation of researchers at any career stage in related fields.

Conferences and Workshops:

  • 4 - 8 September 2023: Summer School
    Introduction to totally disconnected locally compact groups
    This summer school provides an introduction to various aspects of t.d.l.c. groups aimed at graduate students and postgraduate fellows. Topics include Cayley-Abels graphs, homological methods, p-adic Lie groups and self-similarity.

  • 11 - 19 September 2023: Workshop 1
    Totally disconnected locally compact groups from a geometric perspective
    Many discrete geometric structures admit symmetries that are not determined by a finite substructure. This phenomenon is reflected in the non-discreteness of their automorphism group. Conversely, sufficiently non-discrete t.d.l.c. groups admit geometric actions on such structures. This workshop focuses on the above approaches and their interplay.
  • 9 - 13 October 2023: Workshop 2
    Totally disconnected locally compact groups: local to global
    This workshop studies the relationship between local, or small-scale, and global, or large-scale, properties of t.d.l.c. groups, which is more subtle than for Lie groups. Small-scale structure, which manifests both in the topological group structure and the objects on which the groups act, interacts with large-scale properties such as simplicity, amenability and quasi-isometry type.


Simon André (Münster)
Michal Ferov (Newcastle)
Alejandra Garrido (Madrid)
Shirly Geffen (Münster)
David Kerr (Münster)
Colin Reid (Newcastle)
Katrin Tent (Münster)
Stephan Tornier (Newcastle)
George Willis (Newcastle)