Conference proceeding
A canonical basis for Garsia-Procesi modules
Discrete Mathematics and Theoretical Computer Science, v DMTCS Proceedings vol. AN, 22nd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2010)(Proceedings)
01 Jan 2010
Abstract
We identify a subalgebra $\widehat{\mathscr{H}}^+_n$ of the extended affine Hecke algebra $\widehat{\mathscr{H}}_n$ of type $A$. The subalgebra $\widehat{\mathscr{H}}^+_n$ is a u-analogue of the monoid algebra of $\mathcal{S}_n ⋉ℤ_≥0^n$ and inherits a canonical basis from that of $\widehat{\mathscr{H}}_n$. We show that its left cells are naturally labeled by tableaux filled with positive integer entries having distinct residues mod $n$, which we term positive affine tableaux (PAT). We then exhibit a cellular subquotient $\mathscr{R}_1^n$ of $\widehat{\mathscr{H}}^+_n$ that is a $u$-analogue of the ring of coinvariants $ℂ[y_1,\ldots,y_n]/(e_1, \ldots,e_n)$ with left cells labeled by PAT that are essentially standard Young tableaux with cocharge labels. Multiplying canonical basis elements by a certain element $*π ∈ \widehat{\mathscr{H}}^+_n$ corresponds to rotations of words, and on cells corresponds to cocyclage. We further show that $\mathscr{R}_1^n$ has cellular quotients $\mathscr{R}_λ$ that are $u$-analogues of the Garsia-Procesi modules $R_λ$ with left cells labeled by (a PAT version of) the $λ$ -catabolizable tableaux.
On définit une sous-algèbre $\widehat{\mathscr{H}}^+_n$ de l'extension affine de l'algèbre de Hecke \$\widehat{\mathscr{H}}_n$ de type $A$. La sous-algèbre $\widehat{\mathscr{H}}^+_n$ est $u$-analogue à l'algèbre monoïde de $\mathcal{S}_n ⋉ℤ_≥0^n$ et hérite d'une base canonique de $\widehat{\mathscr{H}}_n$. On montre que ses cellules gauches sont naturellement classées par des tableaux remplis d'entiers naturels ayant chacun des restes différents modulo $n$, que l'on nomme Positive Affine Tableaux (PAT). On montre ensuite qu'un sous-quotient cellulaire $\mathscr{R}_1^n$ de $\widehat{\mathscr{H}}^+_n$ est une $u$-analogue de l'anneau des co-invariants $ℂ[y_1,\ldots,y_n]/(e_1, \ldots,e_n)$ avec des cellules gauches classées PAT qui sont essentiellement des tableaux de Young standards avec des labels cochargés. Multiplier les éléments de la base canonique par un certain élément $π ∈ \widehat{\mathscr{H}}^+_n$ correspond à des rotations de mots, et par rapport aux cellules cela correspond à un cocyclage. Plus loin, on montre que $\mathscr{R}_1^n$ a pour quotients cellulaires $\mathscr{R}_λ$ qui sont $u$- analogues aux modules de Garsia-Procesi $R_λ$ avec des cellules gauches définies par (une version PAT) des tableaux $λ$ -catabolisable.
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Details
- Title
- A canonical basis for Garsia-Procesi modules
- Creators
- Jonah Blasiak - University of Chicago
- Publication Details
- Discrete Mathematics and Theoretical Computer Science, v DMTCS Proceedings vol. AN, 22nd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2010)(Proceedings)
- Conference
- 22nd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2010), 22nd (2010)
- Series
- DMTCS Proceedings
- Publisher
- DMTCS
- Resource Type
- Conference proceeding
- Language
- English
- Academic Unit
- Mathematics
- Other Identifier
- 991021862256204721