W*-superrigidity for discrete quantum groups
Operator Algebras
2026-04-15 v2 Group Theory
Quantum Algebra
Abstract
A discrete group is called W*-superrigid if the group can be entirely recovered from the ambient group von Neumann algebra . We introduce an analogous notion for discrete quantum groups. We prove that this strengthened quantum W*-superrigidity property holds for a natural family of co-induced discrete quantum groups. We also prove that, remarkably, most existing families of W*-superrigid groups are not quantum W*-superrigid.
Keywords
Cite
@article{arxiv.2504.03266,
title = {W*-superrigidity for discrete quantum groups},
author = {Milan Donvil and Stefaan Vaes},
journal= {arXiv preprint arXiv:2504.03266},
year = {2026}
}
Comments
v2: minor changes, final version, to appear in Communications in Mathematical Physics