Saved in:
Bibliographic Details
Main Authors: Chowdhury, Sulakhana, Thangavelu, Geetha
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2503.09406
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915194650755072
author Chowdhury, Sulakhana
Thangavelu, Geetha
author_facet Chowdhury, Sulakhana
Thangavelu, Geetha
contents In this article, we study the permutation modules and Young modules of the group algebras of the direct product of symmetric groups $K\mathfrak{S}_{a,b}$, and the walled Brauer algebras $\B_{r,t}(δ)$. In the category of dual Specht-filtered modules, if the characteristic of the field is neither $2$ nor $3$, then the permutation modules are dual Specht filtered, and the Young modules are relative projective cover of the dual Specht modules. We prove that the restriction of the cell modules of $\B_{r,t}(δ)$ to the group algebras of the direct product of the symmetric groups is dual Specht filtered, and the Young modules act as the relative projective cover of the cell modules of $\B_{r,t}(δ)$. Finally, we prove that if $\mathrm{char}~K \neq 2,3$, then the permutation module of $\B_{r,t}(δ)$ can be written as a direct sum of indecomposable Young modules.
format Preprint
id arxiv_https___arxiv_org_abs_2503_09406
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Permutation modules of the walled Brauer algebras
Chowdhury, Sulakhana
Thangavelu, Geetha
Representation Theory
20C30, 05E10, 16D40
In this article, we study the permutation modules and Young modules of the group algebras of the direct product of symmetric groups $K\mathfrak{S}_{a,b}$, and the walled Brauer algebras $\B_{r,t}(δ)$. In the category of dual Specht-filtered modules, if the characteristic of the field is neither $2$ nor $3$, then the permutation modules are dual Specht filtered, and the Young modules are relative projective cover of the dual Specht modules. We prove that the restriction of the cell modules of $\B_{r,t}(δ)$ to the group algebras of the direct product of the symmetric groups is dual Specht filtered, and the Young modules act as the relative projective cover of the cell modules of $\B_{r,t}(δ)$. Finally, we prove that if $\mathrm{char}~K \neq 2,3$, then the permutation module of $\B_{r,t}(δ)$ can be written as a direct sum of indecomposable Young modules.
title Permutation modules of the walled Brauer algebras
topic Representation Theory
20C30, 05E10, 16D40
url https://arxiv.org/abs/2503.09406