SMS scnews item created by Leo Tzou at Fri 12 May 2017 1112
Type: Seminar
Modified: Fri 12 May 2017 1114; Tue 23 May 2017 1541
Distribution: World
Expiry: 12 May 2018
Calendar1: 31 May 2017 1400-1500
CalLoc1: UNSW Red Centre 4082
CalTitle1: The Witt group of braided fusion categories
Auth: leo@ (ltzo2369) in SMS-WASM

Joint Colloquium: Nikshych -- The Witt group of braided fusion categories

A classical theorem of Joyal and Street establishes an equivalence between braided
categorical groups and quadratic forms.  This brings an important geometric insight into
the theory of braided fusion categories: one can treat them as non-commutative geometric
objects.  From this point of view the Drinfeld centers correspond to hyperbolic
quadratic forms.  We use this observation to define a categorical analogue of the
classical Witt group of quadratic forms.  It turns out that the categorical Witt group W
is no longer a torsion group.  We discuss the structure of W and its generalizations:
the super and equivariant categorical Witt groups.  This talk is based on joint works
with Alexei Davydov, Victor Ostrik, and Michael Mueger.

ball Calendar (ICS file) download, for import into your favourite calendar application
ball UNCLUTTER for printing
ball AUTHENTICATE to mark the scnews item as read
School members may try to .