BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Sanaz Pooya DTSTART:20201123T150000Z DTEND:20201123T160000Z DTSTAMP:20260423T035737Z UID:GOBA/9 DESCRIPTION:Title: Hig her Kazhdan projections and Baum-Connes conjectures\nby Sanaz Pooya as part of Groups\, Operators\, and Banach Algebras Webinar\n\n\nAbstract\nT he Baum-Connes conjecture\, if it holds for a certain group\, provides top ological tools to compute the K-theory of its reduced group C*-algebra. Th is conjecture has been confirmed for large classes of groups\, such as ame nable groups\, but also for some Kazhdan's property (T) groups. Property ( T) and its strengthening are driving forces in the search for potential co unterexamples to the conjecture. Having property (T) for a group is charac terised by the existence of a certain projection in the universal group C* -algebra of the group\, known as the Kazhdan projection. It is this projec tion and its analogues in other completions of the group ring\, which obst ruct known methods of proof for the Baum-Connes conjecture. In this talk\, I will introduce a generalisation of Kazhdan projections. Employing these projections we provide a link between surjectivity of the Baum-Connes map and the l²-Betti numbers of the group. A similar relation can be obtaine d in the context of the coarse Baum-Connes conjecture. This is based on jo int work with Kang Li and Piotr Nowak.\n LOCATION:https://researchseminars.org/talk/GOBA/9/ END:VEVENT END:VCALENDAR