activity
20242026
collaborators

6 papers

math.DS2026

Quantitative orbit equivalence for -odometers

Petr Naryshkin, Spyridon Petrakos

We prove that any two -odometers are sub--orbit equivalent, greatly strengthening previous results and giving a definitive picture of quantitative orbit equivalenc…

math.LO2026

Hyper-u-amenablity and Hyperfiniteness of Treeable Equivalence Relations

Petr Naryshkin, Andrea Vaccaro

We introduce the notions of u-amenability and hyper-u-amenability for countable Borel equivalence relations, strong forms of amenability that are implied by hyperfiniteness. We sho…

math.DS2025

Elementary amenability and almost finiteness

David Kerr, Petr Naryshkin

We show that every free continuous action of a countably infinite elementary amenable group on a finite-dimensional compact metrizable space is almost finite. As a consequence, the…

math.DS2025

Almost finiteness and groups of dynamical origin

Petr Naryshkin, Spyridon Petrakos

We introduce the property of having good subgroups for actions of countable discrete groups on compact metrizable spaces, and show that it implies comparison when the acting group…

math.DS2024

URP, comparison, mean dimension, and sharp shift embeddability

Petr Naryshkin

For a free action of an amenable group on a compact metrizable space, we study the Uniform Rokhlin Property (URP) and the conjunction of Uniform Rokhlin Prop…

math.OA2024

Essential freeness, allostery and -stability of crossed products

Eusebio Gardella, Shirly Geffen, Rafaela Gesing +2

We explore classifiability of crossed products of actions of countable amenable groups on compact, metrizable spaces. It is completely understood when such crossed products are sim…