Superinduction for pattern groups

It is well known that the representation theory of the finite group of unipotent upper-triangular matrices U[subscript n] over a finite field is a wild problem. By instead considering approximately irreducible representations (supercharacters), one obtains a rich combinatorial theory analogous to th...

Full description

Bibliographic Details
Main Authors: Marberg, Eric, Thiem, Nathaniel
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:en_US
Published: Elsevier 2015
Online Access:http://hdl.handle.net/1721.1/96168
_version_ 1811076419565912064
author Marberg, Eric
Thiem, Nathaniel
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Marberg, Eric
Thiem, Nathaniel
author_sort Marberg, Eric
collection MIT
description It is well known that the representation theory of the finite group of unipotent upper-triangular matrices U[subscript n] over a finite field is a wild problem. By instead considering approximately irreducible representations (supercharacters), one obtains a rich combinatorial theory analogous to that of the symmetric group, where we replace partition combinatorics with set-partitions. This paper studies Diaconis–Isaacs' concept of superinduction in pattern groups. While superinduction shares many desirable properties with usual induction, it no longer takes characters to characters. We begin by finding sufficient conditions guaranteeing that superinduction is in fact induction. It turns out for two natural embeddings of U[subscript m] in U[subscript n], superinduction is induction. We conclude with an explicit combinatorial algorithm for computing this induction analogous to the Pieri-formulas for the symmetric group.
first_indexed 2024-09-23T10:21:31Z
format Article
id mit-1721.1/96168
institution Massachusetts Institute of Technology
language en_US
last_indexed 2024-09-23T10:21:31Z
publishDate 2015
publisher Elsevier
record_format dspace
spelling mit-1721.1/961682022-09-26T17:23:34Z Superinduction for pattern groups Marberg, Eric Thiem, Nathaniel Massachusetts Institute of Technology. Department of Mathematics Marberg, Eric It is well known that the representation theory of the finite group of unipotent upper-triangular matrices U[subscript n] over a finite field is a wild problem. By instead considering approximately irreducible representations (supercharacters), one obtains a rich combinatorial theory analogous to that of the symmetric group, where we replace partition combinatorics with set-partitions. This paper studies Diaconis–Isaacs' concept of superinduction in pattern groups. While superinduction shares many desirable properties with usual induction, it no longer takes characters to characters. We begin by finding sufficient conditions guaranteeing that superinduction is in fact induction. It turns out for two natural embeddings of U[subscript m] in U[subscript n], superinduction is induction. We conclude with an explicit combinatorial algorithm for computing this induction analogous to the Pieri-formulas for the symmetric group. Stanford University 2015-03-25T14:50:15Z 2015-03-25T14:50:15Z 2009-04 2007-12 Article http://purl.org/eprint/type/JournalArticle 00218693 1090-266X http://hdl.handle.net/1721.1/96168 Marberg, Eric, and Nathaniel Thiem. “Superinduction for Pattern Groups.” Journal of Algebra 321, no. 12 (June 2009): 3681–3703. © 2009 Elsevier Inc. en_US http://dx.doi.org/10.1016/j.jalgebra.2009.03.003 Journal of Algebra Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Elsevier Elsevier
spellingShingle Marberg, Eric
Thiem, Nathaniel
Superinduction for pattern groups
title Superinduction for pattern groups
title_full Superinduction for pattern groups
title_fullStr Superinduction for pattern groups
title_full_unstemmed Superinduction for pattern groups
title_short Superinduction for pattern groups
title_sort superinduction for pattern groups
url http://hdl.handle.net/1721.1/96168
work_keys_str_mv AT marbergeric superinductionforpatterngroups
AT thiemnathaniel superinductionforpatterngroups