activity
20242026
collaborators

6 papers

math.GR2026

Borel dimension growth and hyperfiniteness

Jan Grebík, Andrew S. Marks, Václav Rozhoň +1

We show that every increasing union of Borel graphs of pointwise volume growth at most is hyperfinite, where is the unique real root of $(1 - γ)^3…

math.LO2026

Hyperfiniteness of bounded-to-one actions of commutative monoids

Forte Shinko, Felix Weilacher, Jing Yu

A theorem of Dougherty--Jackson--Kechris states that any equivalence relation generated by a single Borel function is hypersmooth. A well-known open problem is whether this can be…

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

Hyperfiniteness for group actions on trees

Srivatsav Kunnawalkam Elayavalli, Koichi Oyakawa, Forte Shinko +1

We identify natural conditions for a countable group acting on a countable tree which imply that the orbit equivalence relation of the induced action on the Gromov boundary is Bore…

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…

math.LO2024

Asymptotic dimension and hyperfiniteness of generic Cantor actions

Sumun Iyer, Forte Shinko

We show that for a countable discrete group which is locally of finite asymptotic dimension, the generic continuous action on Cantor space has hyperfinite orbit equivalence relatio…