A Quiver Presentation for Solomon's Descent Algebra
Abstract
Description
The descent algebra $Σ(W)$ is a subalgebra of the group algebra $\Q W$ of a finite Coxeter group $W$, which supports a homomorphism with nilpotent kernel and commutative image in the character ring of $W$. Thus $Σ(W)$ is a basic algebra, and as such it has a presentation as a quiver with relations. Here we construct $Σ(W)$ as a quotient of a subalgebra of the path algebra of the Hasse diagram of the Boolean lattice of all subsets of $S$, the set of simple reflections in $W$. From this construction we obtain some general information about the quiver of $Σ(W)$ and an algorithm for the construction of a quiver presentation for the descent algebra $Σ(W)$ of any given finite Coxeter group $W$.
45 pages, 5 figures. v3: corrected typos, updated references; to appear in Adv. Math
45 pages, 5 figures. v3: corrected typos, updated references; to appear in Adv. Math