Robin Tucker-Drob: "Measure Equivalence of Baumslag-Solitar Groups"

mardi 3 sept. 2024, 14:00 → 15:00 Europe/Paris

Abstract: We show that all non-amenable non-unimodular Baumslag-Solitar groups BS(r,s), 2≤ |r|<s, are measure equivalent to each other, thereby completing the measure equivalence classification of Baumslag-Solitar groups. Consequently, each BS(r,s) belongs to one of three measure equivalence classes according to whether it is amenable (|r|=1 or |s|=1), virtually isomorphic to F_n\times Z  (2\leq |r|=|s|), or non-amenable and non-unimodular (2\leq |r|<s). This is joint work with Damien Gaboriau, Antoine Poulin, Anush Tserunyan, and Konrad Wrobel.