BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Milan Donvil (École normale supérieure - PSL\, France) DTSTART:20251117T150000Z DTEND:20251117T160000Z DTSTAMP:20260422T182333Z UID:QGS/134 DESCRIPTION:Title: W* -superrigidity for discrete quantum groups\nby Milan Donvil (École no rmale supérieure - PSL\, France) as part of Quantum Groups Seminar [QGS]\ n\n\nAbstract\nA (countable) group is called W*-superrigid if it is comple tely remembered by its group von Neumann algebra in the following sense: i f another group gives rise to an isomorphic group von Neumann algebra\, th e groups must be isomorphic. In the past fifteen years\, several classes o f W*-superrigid groups have been found. However\, it turns out that many o f these groups are not W*-superrigid in the larger class of compact quantu m groups: their group von Neumann algebras admit different quantum group s tructures. In a recent work with Stefaan Vaes\, we found the first example s of compact quantum groups which are 'quantum W*-superrigid'. To obtain q uantum W*-superrigidity\, we had to combine three different types of resul ts: vanishing of cohomology\, rigidity of (quantum) groups relative to a f amily of (quantum) group automorphisms\, and deformation/rigidity theory. I will explain why each of these three parts is essential and how they com e together to prove our main result.\n LOCATION:https://researchseminars.org/talk/QGS/134/ END:VEVENT END:VCALENDAR