William Q. Erickson

activity

20242026

collaborators

7 papers

math.CO2026

Explicit marginal distributions for permutations with prescribed Robinson-Schensted shape

William Q. Erickson

Given a permutation $I ¨ $ , the Robinson-Schensted correspondence determines a certain partition called the shape of $I ¨ $ . Famously, the shape measures the longest unions of increasi…

math.CO2026

A combinatorial interpretation of the Bernstein degree of unitary highest weight modules

William Q. Erickson, Markus Hunziker

The Bernstein degree ( $Deg$ ) is a fundamental invariant of admissible representations of a real reductive Lie group $G_{R}$ . Our main result concerns the cl…

math.CO2026

Stanley decompositions of modules of covariants

William Q. Erickson, Markus Hunziker

Let $H$ be a complex reductive group, with finite-dimensional representations $W$ and $U$ . The module of covariants for $W$ of type $U$ is the space of all $H$ -equivariant polynomi…

math.RT2025

Unitarity of highest weight Harish-Chandra modules and smoothness of Schubert varieties

Zhanqiang Bai, William Q. Erickson, Markus Hunziker +1

Let $G_{R}$ be a Lie group of Hermitian type, and $L (I^»)$ a highest weight Harish-Chandra module of $G_{R}$ with highest weight $I^»$ . In this article, we exhibit…

math.RT2025

$K$ -type multiplicities in degenerate principal series via Howe duality

Mark Colarusso, William Q. Erickson, Andrew Frohmader +1

Let $K$ be one of the complex classical groups $O_{k}$ , $GL_{k}$ , or $Sp_{2 k}$ . Let $M \subseteq K$ be the block diagonal embedding ${\rm O}_{k_1} \times \cdots \time…

math.CO2025

Tensor invariants for classical groups revisited

William Q. Erickson, Markus Hunziker

We reconsider an old problem, namely the dimension of the $G$ -invariant subspace in $V^{\otimes p} \otimes V^{*\otimes q}$ , where $G$ is one of the classical groups $GL (V)$ ,…

Explicit marginal distributions for permutations with prescribed Robinson-Schensted shape

A combinatorial interpretation of the Bernstein degree of unitary highest weight modules

Stanley decompositions of modules of covariants

Unitarity of highest weight Harish-Chandra modules and smoothness of Schubert varieties

K-type multiplicities in degenerate principal series via Howe duality

Tensor invariants for classical groups revisited

$K$ -type multiplicities in degenerate principal series via Howe duality