Schreier graphs of spinal groups (Aitor Perez Perez, Université de Genève)

15.05.2018 10:30

Spinal groups form a family of branch groups acting on d-regular rooted trees containing many interesting examples, including Grigorchuk's family of groups of intermediate growth. Because of its natural action on the tree, it is interesting to know how their Schreier graphs look like. In this talk we will define the spinal family, provide some examples, describe the Schreier graphs in general and find some of the properties they exhibit. In particular, we will count the number of ends they have, describe how they partition into isomorphism classes, tell under which conditions the action is linearly repetitive or Boshernitzan (properties related to symbolic dynamics) and find out what their spectra look like.

Lieu

Room 623, Séminaire "Groupes et Géométrie"

entrée libre