Published September 2020 | Version Published + Accepted Version
Journal Article Open

Kazhdan groups have cost 1

  • 1. ROR icon University of Cambridge
  • 2. ROR icon Alfréd Rényi Institute of Mathematics
  • 3. ROR icon Budapest University of Technology and Economics

Abstract

We prove that every countably infinite group with Kazhdan's property (T) has cost 1, answering a well-known question of Gaboriau. It remains open if they have fixed price 1.

Additional Information

© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Received: 26 October 2018 / Accepted: 16 February 2020 / Published online: 2 April 2020. Open access funding provided by Alfréd Rényi Institute of Mathematics. We are grateful to Miklós Abért for many helpful discussions, to MFO, Oberwolfach, where this work was conceived, and to Damien Gaboriau and Russ Lyons for comments on the manuscript. We also thank the anonymous referees for their thorough reading and helpful comments. The work of GP was supported by the ERC Consolidator Grant 772466 "NOISE", and by the Hungarian National Research, Development and Innovation Office, NKFIH Grant K109684.

Attached Files

Published - Hutchcroft-Pete2020_Article_KazhdanGroupsHaveCost1.pdf

Accepted Version - 1810.11015.pdf

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Additional details

Identifiers

Eprint ID
110997
Resolver ID
CaltechAUTHORS:20210922-193307950

Related works

Funding

Alfréd Rényi Institute of Mathematics
European Research Council (ERC)
772466
Hungarian National Research, Development, and Innovation Office (NKFIH)
K109684

Dates

Created
2021-09-27
Created from EPrint's datestamp field
Updated
2021-09-27
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Mathematics Department