BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:Geometric Group Theory (GGT) Seminar
SUMMARY:Ramanujan cubical complexes and non-residually fin
ite groups in dimensions three and higher - Alina
Vdovina (Newcastle University)
DTSTART;TZID=Europe/London:20200207T134500
DTEND;TZID=Europe/London:20200207T144500
UID:TALK137782AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/137782
DESCRIPTION:Ramanujan graphs were first considered by Margulis
and Lubotzky\, Phillips\, Sarnak to get graphs wi
th optimal spectral properties. In our days the th
eory of expander graphs and\, in particular\, Rama
nujan graphs is well developed\, but the questions
is what is the best definition of a higher-dimens
ional expander is still wide open. There are sever
al approaches\, suggested by Gromov\, Lubotzky\, A
lon and others\, but the cubical complexes were no
t much investigated from this point of view.\n\nIn
this talk I will give new explicit examples of cu
bical Ramanujan complexes\, discuss possible devel
opments and show how to get non-residually finite
groups from Ramanujan complexes.
LOCATION:CMS\, MR13
CONTACT:
END:VEVENT
END:VCALENDAR