English

W*-superrigidity for discrete quantum groups

Operator Algebras 2026-04-15 v2 Group Theory Quantum Algebra

Abstract

A discrete group GG is called W*-superrigid if the group GG can be entirely recovered from the ambient group von Neumann algebra L(G)L(G). 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

R2 v1 2026-06-28T22:46:26.576Z