Measured groupoids beyond equivalence relations and group actions
Group Theory
2025-10-15 v2 Operator Algebras
Abstract
We construct the first examples of genuine ergodic discrete measured groupoids that are not isomorphic to any equivalence relation or transformation groupoid. We use a construction due to B.H. Neumann of an uncountable family of pairwise non-isomorphic 2-generated groups for our result.
Cite
@article{arxiv.2410.15147,
title = {Measured groupoids beyond equivalence relations and group actions},
author = {Soham Chakraborty},
journal= {arXiv preprint arXiv:2410.15147},
year = {2025}
}
Comments
v2, minor changes; to appear in Groups, Geometry and Dynamics