BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Detecting free factors in profinite completions - Alejandra Garrid
 o (Universidad Autónoma de Madrid)
DTSTART:20221111T134500Z
DTEND:20221111T144500Z
UID:TALK182816@talks.cam.ac.uk
CONTACT:76015
DESCRIPTION:If one is interested in a finitely generated residually finite
  group\, it is natural to ask to what extent it is determined by its profi
 nite completion. The extent to which this is a hard question in general is
  shown by the fact that it is not yet known whether a finitely generated f
 ree group is determined by its profinite completion (a question attributed
  to Remeslennikov). A variant of Remeslennikov's question is whether a fre
 e factor of a group G can be detected from its profinite completion: if G 
 has a subgroup H\, whose closure in the profinite completion of G is a pro
 finite free factor\, must H be a free factor of G? This question is still 
 hard\, with positive known answer only when G itself is a free group. \n\n
  \n\nI will report on joint work with A. Jaikin in which we provide a new
  proof of the above positive answer and extend it to the case when G is vi
 rtually free. The methods might be extended to other classes of groups if 
 some interesting questions are answered on their completed group algebras.
 \n\n
LOCATION:Zoom
END:VEVENT
END:VCALENDAR