Baumslag-Solitar groups, relative profinite completions and measure equivalence rigidity
Baumslag-Solitar groups, relative profinite completions and measure equivalence rigidity
We introduce an algebraic invariant for aperiodic inclusions of probability measure preserving (pmp) equivalence relations. We use this invariant to prove that every stable orbit equivalence between free pmp actions of direct products of non-amenable Baumslag–Solitar groups whose canonical subgroup acts aperiodically, forces the number of factors of the products …