BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//University of California\, Berkeley//UCB Events Calendar//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:America/Los_Angeles
BEGIN:STANDARD
TZOFFSETFROM:-0700
TZOFFSETTO:-0800
DTSTART:19701029T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:19700402T020000
TZOFFSETFROM:-0800
TZOFFSETTO:-0700
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20170321T104254Z
DTSTART;TZID=America/Los_Angeles:20170405T161000
DTEND;TZID=America/Los_Angeles:20170405T170000
TRANSP:OPAQUE
SUMMARY:Topology Seminar (Main Talk): Additive Invariants of Knots\, Links\, and Spatial Graphs in 3-manifolds.
UID:108182-ucb-events-calendar@berkeley.edu
ORGANIZER;CN="UC Berkeley Calendar Network":
LOCATION:3 Evans Hall
DESCRIPTION:Scott Taylor\, Colby College\n\nTunnel number\, higher genus bridge number\, and Gabai width are classical knot invariants that are additive under connected sum for some classes of knots\, but not for others. I'll explain variations of these classical invariants that are defined for almost all (3-manifold\, graph) pairs\, that detect the unknot in the 3-sphere\, and that are additive under connected sum and trivalent vertex sum. The proofs of these facts rely on a new version of thin position for (3-manifold\, graph) pairs. Harnessing the relationship between these new invariants and tunnel number\, we'll prove a theorem whose statement is a combination of the statements of theorems of Scharlemann-Schultens and Morimoto\; it gives a lower bound on the tunnel number of the connected sum of knots in terms of the number and tunnel number of the summands. This is joint work with Maggy Tomova.
URL:http://events.berkeley.edu/index.php/calendar/sn/pubaff.html?event_ID=108182&view=preview
SEQUENCE:0
CLASS:PUBLIC
CREATED:20170321T104254Z
LAST-MODIFIED:20170321T104254Z
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
X-MICROSOFT-CDO-INSTTYPE:0
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-OWNERAPPTID:-1
END:VEVENT
END:VCALENDAR