BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250808T040017EDT-8833JO9Rwf@132.216.98.100 DTSTAMP:20250808T080017Z DESCRIPTION:Sharp threshold for Property (T) in the hexagonal model for ran dom groups.\n\nA random group in the hexagonal model is a group given by t he presentation where R is a set of random words of length 6 over the set S. We consider properties of such a group as the cardinality of S goes to infinty. Our main goal in the presentation is to prove that as the cardina lity of the set R increases (we increase the density defined as d =(1) *lo g_{|S|}(|R|)) there is a sharp transition between not having Property (T) and having Property (T) for such group (this threshold is at density d=1/3 ). First we will present a quick survey about what is known at the moment about Property (T) for random groups. To proof thie main result we will pr esent a new method of constructing some good system of walls on the Cayley complex of a random group. This will allows us to find a proper action of a random group on a CAT(0) cube complex. The main idea behind constructin g our system of walls is to take hypergraphs in the Cayley complex (as Wis e and OIllivier did in their paper about cubulating random groups) and the n correct them to make them embedded trees.\n DTSTART:20161102T190000Z DTEND:20161102T200000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Tomasz\, Odrzygozdz URL:/mathstat/channels/event/tomasz-odrzygozdz-263856 END:VEVENT END:VCALENDAR