English

A proof of the $\frac{n!}{2}$ conjecture for hook shapes

Combinatorics 2022-10-24 v2 Representation Theory

Abstract

A well-known representation-theoretic model for the transformed Macdonald polynomial H~μ(Z;t,q)\widetilde{H}_\mu(Z;t,q), where μ\mu is an integer partition, is given by the Garsia-Haiman module Hμ\mathcal{H}_\mu. We study the n!k\frac{n!}{k} conjecture of Bergeron and Garsia, which concerns the behavior of certain kk-tuples of Garsia-Haiman modules under intersection. In the special case that μ\mu has hook shape, we use a basis for Hμ\mathcal{H}_\mu due to Adin, Remmel, and Roichman to resolve the n!2\frac{n!}{2} conjecture by constructing an explicit basis for the intersection of two Garsia-Haiman modules.

Keywords

Cite

@article{arxiv.2203.15146,
  title  = {A proof of the $\frac{n!}{2}$ conjecture for hook shapes},
  author = {Sam Armon},
  journal= {arXiv preprint arXiv:2203.15146},
  year   = {2022}
}

Comments

Final version; 12 pages, clarified proof of Theorem 4.3. To appear in Annals of Combinatorics