Weakly maximal subgroups of branch groups (Paul-Henry Leemann, ENS Lyon)

31.03.2020 16:30

The first Grigorchuk group and many other branch groups have the property that all their maximal subgroups are of finite index. The next step is to understand weakly maximal subgroups, i.e. maximal among subgroups of infinite index. One class of such subgroups are parabolic subgroups, but what about the others? We will give the full description in the case of the first Grigorchuk group and discuss the general case.

Lieu

Join the Zoom session https://unige.zoom.us/j/696379617, Séminaire "Groupes et Géométrie", Att. heure inhabituelle

entrée libre