Fully commutative elements in affine Coxeter groups

Seminar
Speaker
Riccardo Biagioli (Université Claude Bernard Lyon 1)
Date
15/12/2019 - 15:30 - 14:00Add to Calendar 2019-12-15 14:00:00 2019-12-15 15:30:00 Fully commutative elements in affine Coxeter groups An element of a Coxeter group W is fully commutative if any two of its reduced decompositions are related by a series of transpositions of adjacent commuting generators. These elements were extensively studied by Stembridge, in the finite case. They index naturally a basis of the generalized Temperley–Lieb algebra of W. In this talk, we give explicit descriptions of fully commutative elements when W is an affine Coxeter group. Using our characterizations we then enumerate these elements according to their Coxeter length, and we show that the corresponding generating function is ultimately periodic in each type. Based on joint work with F. Jouhet and P. Nadeau. Room 201, Math and CS Building (Bldg. 216) אוניברסיטת בר-אילן - Department of Mathematics mathoffice@math.biu.ac.il Asia/Jerusalem public
Place
Room 201, Math and CS Building (Bldg. 216)
Abstract

An element of a Coxeter group W is fully commutative if any two of its reduced decompositions are related by a series of transpositions of adjacent commuting generators. These elements were extensively studied by Stembridge, in the finite case. They index naturally a basis of the generalized Temperley–Lieb algebra of W.

In this talk, we give explicit descriptions of fully commutative elements when W is an affine Coxeter group. Using our characterizations we then enumerate these elements according to their Coxeter length, and we show that the corresponding generating function is ultimately periodic in each type.

Based on joint work with F. Jouhet and P. Nadeau.

Last Updated Date : 13/12/2019