Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-25T16:44:25.859Z Has data issue: false hasContentIssue false

CHARACTERIZATIONS OF LOCALLY FINITE ACTIONS OF GROUPS ON SETS

Published online by Cambridge University Press:  04 September 2017

EDUARDO SCARPARO*
Affiliation:
Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen, Denmark e-mail: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We show that an action of a group on a set X is locally finite if and only if X is not equidecomposable with a proper subset of itself. As a consequence, a group is locally finite if and only if its uniform Roe algebra is finite.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 2017 

References

REFERENCES

1. Glasner, Y. and Monod, N., Amenable actions, free products and a fixed point property, Bull. London Math. Soc. 39 (1) (2007), 138150.Google Scholar
2. Juschenko, K. and Monod, N. Cantor systems, piecewise translations and simple amenable groups, Ann. Math. 178 (2) (2013), 775787.Google Scholar
3. Kellerhals, J., Monod, N. and Rørdam, M., Non-supramenable groups acting on locally compact spaces, Doc. Math. 18(2013), 15971626.Google Scholar
4. Shalom, Y., Harmonic analysis, cohomology, and the large-scale geometry of amenable groups, Acta Mathematica 192 (2) (2004), 119185.Google Scholar
5. Silva, P. V. and Soares, F., Howson's property for semidirect products of semilattices by groups, Commun. Algebra 44 (6) (2016), 24822494.Google Scholar
6. Wagon, S., The Banach–Tarski paradox, vol. 24 (Cambridge University Press, Cambridge, 1993).Google Scholar
7. Wei, S., On the quasidiagonality of Roe algebras, Sci. China Math. 54 (5) (2011), 10111018.Google Scholar
8. Żuk, A., On an isoperimetric inequality for infinite finitely generated groups, Topology 39 (5) (2000), 947956.Google Scholar