SMS scnews item created by Hannah Bryant at Fri 13 Aug 2021 1247
Type: Seminar
Distribution: World
Expiry: 26 Aug 2021
Calendar1: 26 Aug 2021 1530-1700
CalLoc1: Online via Zoom
Auth: hannahb@10.48.19.150 (hbry8683) in SMS-SAML

# SMRI Algebra and Geometry Online: Ko -- A singular Coxeter presentation

SMRI Algebra and Geometry Online
’A singular Coxeter presentation’
Hankyung Ko (Uppsala University)

Thursday, Aug 26
3:30pm-5:30pm (AEST)
Register:
https://uni-sydney.zoom.us/meeting/register/tZYqcO2uqDkpE9DpzrQ6bJCXU2M0pdUMXo-k

Abstract: A Coxeter system is a presentation of a group by generators and a specific
form of relations, namely the braid relations and the reflection relations. The
Coxeter presentation leads to, among others, a similar presentation of the
(Iwahori-)Hecke algebras and the Kazhdan-Lusztig theory, which provides combinatorial
answers to major problems in Lie theoretic representation theory and geometry.
Extending such applications to the singular land’ requires the singular version of
the Hecke algebra. Underlying combinatorics of the singular Hecke algebra/category
comes from the parabolic double cosets and is the first step in understanding the
singular Hecke category. In this talk, I will present a Coxeter theory of the
parabolic double cosets developed in a joint work with Ben Elias. In particular, I
will explain a generalization of the reduced expressions and describe the braid and
non-braid relations.

Biography: Hangyung Ko is a postdoc researcher at Matematiska institutionen, Uppsala
University, working on Lie theoretic representation theory. She is mainly interested
in representation theory of algebraic groups in positive characteristic, category O,
higher(categorical) representation theory, and related topics like Coxeter groups
and their Hecke algebras, Soergel bimodules, quantum groups, R-matrices and
K-matrices, polynomial functors and functor cohomology, category theory and
homological algebra.

Note: These seminars will be recorded, including participant questions (participants
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