Hecke algebras of simply-laced type with independent parameters

Abstract

We study the (complex) Hecke algebra ${\mathcal{H}}_S(\mathbf{q})$ of a finite simply-laced Coxeter system $(W,S)$ with independent parameters $\mathbf{q}\in {\left(\mathbb{C}\setminus \{\text{roots of unity}\}\right)}^S$. We construct its irreducible representations and projective indecomposable representations. We obtain the quiver of this algebra and determine when it is of finite representation type. We provide decomposition formulas for induced and restricted representations between the algebra ${\mathcal{H}}_S(\mathbf{q})$ and the algebra ${\mathcal{H}}_R(\mathbf{q}{|}_R)$ with $R\subseteq S$. Our results demonstrate an interesting combination of the representation theory of finite Coxeter groups and their 0-Hecke algebras, including a two-sided duality between the induced and restricted representations.

20 pages; to appear in Algebraic Combinatorics