A Coboundary Temperely-Lieb Category for $\mathfrak{sl}_2$-Crystals

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Alqady, Moaaz, Stroiński, Mateusz
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915176288092160
author Alqady, Moaaz
Stroiński, Mateusz
author_facet Alqady, Moaaz
Stroiński, Mateusz
contents By considering a suitable renormalization of the Temperley--Lieb category, we study its specialization to the case $q=0$. Unlike the $q\neq 0$ case, the obtained monoidal category, $\mathcal{TL}_0(\Bbbk)$, is not rigid or braided. We provide a closed formula for the Jones--Wenzl projectors in $\mathcal{TL}_0(\Bbbk)$ and give semisimple bases for its endomorphism algebras. We explain how to obtain the same basis using the representation theory of finite inverse monoids, via the associated Möbius inversion. We then describe a coboundary structure on $\mathcal{TL}_0(\Bbbk)$ and show that its idempotent completion is coboundary monoidally equivalent to the category of $\mathfrak{sl}_{2}$-crystals. This gives a diagrammatic description of the commutor for $\mathfrak{sl}_{2}$-crystals defined by Henriques and Kamnitzer and of the resulting action of the cactus group. We also study fiber functors of $\mathcal{TL}_0(\Bbbk)$ and discuss how they differ from the $q\neq 0$ case.
format Preprint
id arxiv_https___arxiv_org_abs_2502_05732
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Coboundary Temperely-Lieb Category for $\mathfrak{sl}_2$-Crystals
Alqady, Moaaz
Stroiński, Mateusz
Representation Theory
Combinatorics
Quantum Algebra
17B37 (Primary) 05E10 (Secondary)
By considering a suitable renormalization of the Temperley--Lieb category, we study its specialization to the case $q=0$. Unlike the $q\neq 0$ case, the obtained monoidal category, $\mathcal{TL}_0(\Bbbk)$, is not rigid or braided. We provide a closed formula for the Jones--Wenzl projectors in $\mathcal{TL}_0(\Bbbk)$ and give semisimple bases for its endomorphism algebras. We explain how to obtain the same basis using the representation theory of finite inverse monoids, via the associated Möbius inversion. We then describe a coboundary structure on $\mathcal{TL}_0(\Bbbk)$ and show that its idempotent completion is coboundary monoidally equivalent to the category of $\mathfrak{sl}_{2}$-crystals. This gives a diagrammatic description of the commutor for $\mathfrak{sl}_{2}$-crystals defined by Henriques and Kamnitzer and of the resulting action of the cactus group. We also study fiber functors of $\mathcal{TL}_0(\Bbbk)$ and discuss how they differ from the $q\neq 0$ case.
title A Coboundary Temperely-Lieb Category for $\mathfrak{sl}_2$-Crystals
topic Representation Theory
Combinatorics
Quantum Algebra
17B37 (Primary) 05E10 (Secondary)
url https://arxiv.org/abs/2502.05732