Boundary 2-transitive automorphism groups of trees
Event details
| Date | 08.12.2016 |
| Hour | 13:00 › 14:00 |
| Speaker | Nicolas Radu |
| Location |
MA 31
|
| Category | Conferences - Seminars |
Let T be a locally finite tree all of whose vertices have valency at least 6. In this talk, we will be interested in closed subgroups of Aut(T) acting 2-transitively on the set of ends of T and whose local action at each vertex contains the alternating group. The main result I will present is a full classification of these groups, up to isomorphism. The outcome of the classification is a countable family of group, most of which are new, and all containing a simple subgroup of index ≤ 8. I will also explain what makes the assumption of 2-transitivity on the boundary natural and discuss some direct consequences of the result.
Practical information
- Informed public
- Free