BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20251105T133657EST-8842usCHFV@132.216.98.100
DTSTAMP:20251105T183657Z
DESCRIPTION:Title: SL_2(R) representations of knot groups and an extended L
 in invariant\n\nAbstract: I'll discuss some work in progress with Nathan D
 unfield. In the 90's\, X.S. Lin defined a Casson-style invariant of knots 
 by counting SU(2) representations of the knot group with fixed holonomy al
 ong the meridian. This invariant was subsequently shown to be equivalent t
 o the Levine-Tristam signature. I'll describe a variant of Lin's construct
 ion which counts both SU(2) and SL_2(R) representations of the knot group.
  Lifting to the universal cover widetilde{SL}_2(R) allows us to define an 
 enhanced Lin invariant\, which is a Laurent polynomial rather than just an
  integer. I'll give some applications (including a new proof of the Riley 
 conjecture) and discuss a conjecture about the enhanced invariant of L-spa
 ce knots.\n
DTSTART:20180420T150000Z
DTEND:20180420T160000Z
LOCATION:Room PK-5115 \, CA\, Pavillon President-Kennedy
SUMMARY:Jacob Rasmussen\, Cambridge University
URL:/mathstat/channels/event/jacob-rasmussen-cambridge
 -university-286619
END:VEVENT
END:VCALENDAR