BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20250916T064608EDT-73270nhVUO@132.216.98.100
DTSTAMP:20250916T104608Z
DESCRIPTION:Elementary amenable groups and the space of marked groups.\n\nT
 he space of marked groups is a compact Polish space that parameterizes all
  countable groups. This space allows for tools from descriptive set theory
  to be applied to study group-theoretic questions. The class of elementary
  amenable groups is the smallest class that contains the abelian groups an
 d the finite groups and that is closed under group extension\, taking subg
 roups\, taking quotients\, and taking countable directed unions. In this t
 alk\, we first give a characterization of elementary amenable marked group
 s in terms of well-founded trees. We then show the set of elementary amena
 ble marked groups is coanalytic and non-Borel. This gives a new proof of a
  theorem of Grigorchuk: There are finitely generated amenable non-elementa
 ry amenable groups.\n
DTSTART:20170307T200000Z
DTEND:20170307T210000Z
LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue 
 Sherbrooke Ouest
SUMMARY:Phillip Wesolek\, Binghamton
URL:/mathstat/channels/event/phillip-wesolek-binghamto
 n-266719
END:VEVENT
END:VCALENDAR