Carə tuttə, Vi invitiamo al seminario dei Baby Geometri della prossima settimana: Martedì 19 Novembre 2024, alle ore 11:30 Presso l’Aula Seminari del Dipartimento di Matematica Julian Wyckowski (Università di Cambridge) terrà un seminario dal titolo: Three notions of accessibility for profinite groups acting on profinite trees di cui riporto l'abstract: The theory of groups acting on trees—attributed to Bass and Serre—provides a rich framework for the understanding of structural and homological properties of discrete groups. In this talk, I will introduce the profinite analogue of this theory, developed by Melnikov, Zalesskii and Ribes. I will outline some of the difficulties encountered when passing from the discrete to the profinite world, as well as some solutions. I will also introduce three notions of accessibility in the context of profinite/pro-p groups acting on profinite/pro-p trees and discuss a result of mine as well as two open questions regarding accessibility. Time permitting, I will outline some applications to other topics in profinite rigidity. Vi ricordiamo che potrete trovare informazioni sui prossimi seminari sul nostro sito https://sites.google.com/view/babygeometri. Tutte le persone interessate sono invitate a partecipare. A presto, Elena, Pietro, Alessio, Giovanni, Ervin