3 papers
math.LO2025
Realizations of countable Borel equivalence relations
Joshua Frisch, Alexander Kechris, Forte Shinko +1
We study topological realizations of countable Borel equivalence relations, including realizations by continuous actions of countable groups, with additional desirable properties.…
math.GR2025
Poisson boundary of group extensions
Anna Erschler, Joshua Frisch
Given a finitely generated group, the well-known Stability Problem asks whether the non-triviality of the Poisson-Furstenberg boundary (which is equivalent to the existence of non-…
math.LO2024
Hyper-hyperfiniteness and complexity
Joshua Frisch, Forte Shinko, Zoltan Vidnyanszky
We show that if there exists a countable Borel equivalence relation which is hyper-hyperfinite but not hyperfinite then the complexity of hyperfinite countable Borel equivalence re…