BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jacek Krajczok (Vrije Universiteit Brussel) DTSTART:20240228T200000Z DTEND:20240228T210000Z DTSTAMP:20260420T053532Z UID:NYC-NCG/153 DESCRIPTION:Title: Approximation properties of discrete quantum groups\nby Jacek Krajcz ok (Vrije Universiteit Brussel) as part of Noncommutative geometry in NYC\ n\n\nAbstract\nIt is a classical result in abstract harmonic analysis\, th at discrete group G is amenable if and only if its group von Neumann algeb ra vN(G) has weak* CPAP (completely positive approximation property). Ther e is also a variant of this result for weak amenability: G is weakly amena ble if and only if vN(G) has weak* CBAP (completely bounded approximation property). These equivalences remain true also for unimodular discrete qua ntum groups\, which form a class of objects strictly containing discrete g roups. It is however an open question\, whether approximation properties o f vN(G) imply analogous one for G\, if G is a non-unimodular quantum group . During the talk I will discuss how one can obtain positive results by co nsidering vN(G) not just as a von Neumann algebra\, but as an operator mod ule over $L^1(\\hat{G})$. If time permits\, I will also discuss a recent r esult about multiplicativity of Cowling-Haagerup (weak amenability) consta nt.\n LOCATION:https://researchseminars.org/talk/NYC-NCG/153/ END:VEVENT END:VCALENDAR