Advanced Seminar on Group Theory

Lehrstuhl für Algebra und Zahlentheorie

Wintersemester 2022/23

Where & When:
The usual time is Tuesday in the morning in seminar room 03.73.
Content:
Advanced topics in group theory are discussed in short series of talks and guest lectures.
Organizers:
Prof. Dr. Benjamin Klopsch & Iker de las Heras & Luca Di Gravina

Research talks

Tue 18.10.22, 10:30-12:00
Seminar room 03.73
Matteo Pintonello
Abelian splittings of pro-p right angled Artin groups
Tue 20.12.22, 10:00-11:30
Seminar room 03.73
Anitha Thillaisundaram

Beauville structures for quotients of infinite Grigorchuk-Gupta-Sidki groups acting on the pn-adic tree

Groups of surfaces isogenous to a higher product of curves can be characterised by a purely group-theoretic condition, which is the existence of a so-called Beauville structure. Gul and Uria-Albizuri showed that quotients of the periodic Grigorchuk-Gupta-Sidki groups, GGS-groups for short, that act on the p-adic tree, admit Beauville structures. We extend their result by showing that quotients of infinite periodic GGS-groups, that act on the pn-adic tree, also admit Beauville structures for all primes p and positive integers n. This is joint work with Elena Di Domenico and Şükran Gül.

Bass-Serre theory (programme)

The goal of this seminar is to give an introduction to Bass-Serre theory, a branch of modern geometric group theory which studies structural properties of groups by exploiting their action on trees. See the programme for more details.

Main references:

  1. L. Ribes and P. Zalesskii, Pro-p trees and applications, in New Horizons in pro-p groups, Springer, 2000. link
  2. J.P. Serre, Trees, Springer, 1980. link
Tue 08.11.22, 10:30-12:00
Seminar room 03.73
Margherita Piccolo
Amalgams
Tue 15.11.22, 10:00-11:30
Seminar room 03.73
Lucia Morotti
Trees and free groups
Tue 22.11.22, 10:00-11:30
Seminar room 03.73
Iker de las Heras
Trees and amalgams
Tue 29.11.22, 10:00-11:30
Seminar room 03.73
Giada Serafini
Structure of a group acting on a tree I
Tue 06.12.22, 10:00-11:30
Seminar room 03.73
Daniel Echtler
Structure of a group acting on a tree II
Tue 13.12.22, 10:00-11:30
Seminar room 03.73
Thomas Smith

Amalgams and fixed points

Tue 10.01.23, 10:00-11:30
Seminar room 03.73
Djurre Tijsma

The tree of SL2 over a local field I

Tue 17.01.23, 10:00-11:30
Seminar room 03.73
Martina Conte

The tree of SL2 over a local field II

Tue 24.01.23, 10:00-11:30
Seminar room 03.73
Luca Di Gravina

Profinite graphs and pro-p trees

Tue 31.01.23, 10:00-11:30
Seminar room 03.73
Fabian Korthauer

Pro-p groups acting on pro-p trees

Archive