Logo image
Cohomology of hyperfinite Borel actions
Journal article   Open access   Peer reviewed

Cohomology of hyperfinite Borel actions

Sergey Bezuglyi and Shrey Sanadhya
Groups, geometry and dynamics, Vol.15(4), pp.1363-1398
01/01/2021
DOI: 10.4171/GGD/633
url
https://doi.org/10.4171/GGD/633View
Published (Version of record) Open Access

Abstract

We study cocycles of countable groups F of Borel automorphisms of a standard Borel space (X, B) taking values in a locally compact second countable group G. We prove that for a hyperfinite group F the subgroup of coboundaries is dense in the group of cocycles. We describe all Borel cocycles of the 2-odometer and show that any such cocycle is cohomologous to a cocycle with values in a countable dense subgroup H of G. We also provide a Borel version of Gottschalk-Hedlund theorem.
Mathematics Physical Sciences Science & Technology

Details

Metrics

7 Record Views
Logo image