Restricting supercharacters of the finite group of unipotent uppertriangular matrices

dc.creatorThiem, Nathaniel
dc.creatorVenkateswaran, Vidya
dc.date2007-12-07
dc.date.accessioned2026-07-07T08:48:05Z
dc.date.available2026-07-07T08:48:05Z
dc.descriptionIt is well-known that the representation theory of the finite group of unipotent upper-triangular matrices $U_n$ 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 the supercharacter theory of a family of subgroups that interpolate between $U_{n-1}$ and $U_n$. We supply several combinatorial indexing sets for the supercharacters, supercharacter formulas for these indexing sets, and a combinatorial rule for restricting supercharacters from one group to another. A consequence of this analysis is a Pieri-like restriction rule from $U_n$ to $U_{n-1}$ that can be described on set-partitions (analogous to the corresponding symmetric group rule on partitions).
dc.identifierhttps://arxiv.org/abs/0712.1237
dc.identifierhttp://arxiv.org/abs/0712.1237
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/143825
dc.subjectRepresentation Theory
dc.subjectCombinatorics
dc.subjectGroup Theory
dc.subject20C99
dc.titleRestricting supercharacters of the finite group of unipotent uppertriangular matrices
dc.typetext

Files

Collections