Braid Groups and Euclidean Simplices Seminar - Elizabeth Leyton Chisholm

Event Date: 

Wednesday, May 13, 2015 -
2:00pm to 3:00pm

Event Location: 

  • 6635 South Hall

Event Price: 

Free

Event Contact: 

Michael Dougherty

Email: dougherty@math.ucsb.edu

  • Discrete Geometry Seminar

In the early 2000s, Daan Krammer and Stephen Bigelow independently proved that braid groups are linear. They used the Lawrence-Krammer-Bigelow (LKB) representation for generic values of its variables q and t. The t variable is related to the Garside structure of the braid group used in Krammer's algebraic proof. The q variable, associated with the dual Garside structure of the braid group, has received less attention.

In this talk we give a geometric interpretation of the q portion of the LKB representation in terms of an action of the braid group on the space of non-degenerate euclidean simplices. In our interpretation, braid group elements act by systematically reshaping (and relabeling) euclidean simplices. The reshapings associated to the simple elements in the dual Garside structure of the braid group are of an especially elementary type that we call relabeling and rescaling.