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:Differential Geometry and Topology Seminar
SUMMARY:Cohomological dimension and engulfing - Will Caven
dish\, Oxford
DTSTART;TZID=Europe/London:20121017T160000
DTEND;TZID=Europe/London:20121017T170000
UID:TALK39879AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/39879
DESCRIPTION:Given a group G and a subgroup H of G\, H is said
to be\nengulfed in G if there exists a homomorphis
m f from G to a\nfinite group such that f(H) is pr
operly contained in f(G).\nThe statement that H is
engulfed in G can therefore be thought of\nas say
ing that H "looks smaller" than G from the perspec
tive of\nmaps to finite groups. In this talk we w
ill discuss the following\nquestion: if H looks sm
aller than G from the perspective of\ncohomologica
l dimension\, is H necessarily engulfed? While th
ere are\nmany well-known examples that show that t
he answer to this question is\nno in general\, we
will show that engulfing is guaranteed when the\nc
ohomology rings of objects called mapping solenoid
s associated to the\npair (G\,H) satisfy certain f
initeness conditions.
LOCATION:MR13
CONTACT:Ivan Smith
END:VEVENT
END:VCALENDAR