English

W*-superrigidity for groups with infinite center

Operator Algebras 2025-09-15 v3 Group Theory

Abstract

We construct discrete groups GG with infinite center that are nevertheless W*-superrigid, meaning that the group von Neumann algebra L(G)L(G) fully remembers the group GG. We obtain these rigidity results both up to isomorphisms and up to virtual isomorphisms of the groups and their von Neumann algebras. Our methods combine rigidity results for the quotient of these groups by their center with rigidity results for their 2-cohomology.

Keywords

Cite

@article{arxiv.2410.13417,
  title  = {W*-superrigidity for groups with infinite center},
  author = {Milan Donvil and Stefaan Vaes},
  journal= {arXiv preprint arXiv:2410.13417},
  year   = {2025}
}

Comments

v3: minor changes, final version, to appear in Advances in Mathematics

R2 v1 2026-06-28T19:25:38.234Z