English
Related papers

Related papers: Decomposition matrices for low rank unitary groups

200 papers

We study the modular representation theory of the symmetric and alternating groups. One of the most natural ways to label the irreducible representations of a given group or algebra in the modular case is to show the unitriangularity of the…

Representation Theory · Mathematics 2020-12-09 Olivier Brunat , Jean-Baptiste Gramain , Nicolas Jacon

We consider one-plaquette unitary matrix model at finite $N$ using exact expression of the partition function for both SU($N$) and U($N$) groups.

High Energy Physics - Lattice · Physics 2020-03-04 Raghav G. Jha

In this tutorial, exponentiation and factorization (decomposition) formulas are derived and discussed for common matrix operators that arise in studies of classical dynamics, linear and nonlinear optics, and special relativity. To…

Optics · Physics 2025-08-26 C. J. McKinstrie , M. V. Kozlov

We study several variants of decomposing a symmetric matrix into a sum of a low-rank positive semidefinite matrix and a diagonal matrix. Such decompositions have applications in factor analysis and they have been studied for many decades.…

Optimization and Control · Mathematics 2023-10-02 Levent Tunçel , Stephen A. Vavasis , Jingye Xu

Universally decodable matrices can be used for coding purposes when transmitting over slow fading channels. These matrices are parameterized by positive integers $L$ and $n$ and a prime power $q$. Based on Pascal's triangle we give an…

Information Theory · Computer Science 2007-07-13 Pascal O. Vontobel , Ashwin Ganesan

We give an algorithm for computing matrix corepresentations for special linear and special unitary quantum groups using a combinatorial re-indexing of basis elements.

Quantum Algebra · Mathematics 2008-09-19 Clark Alexander

We derive the matrix elements of generators of unitary irreducible representations of SL(2,C) with respect to basis states arising from a decomposition into irreducible representations of SU(1,1). This is done with regard to a discrete…

General Relativity and Quantum Cosmology · Physics 2011-01-25 Florian Conrady , Jeff Hnybida

Totally equimodular matrices generalize totally unimodular matrices and arise in the context of box-total dual integral polyhedra. This work further explores the parallels between these two classes and introduces foundational building…

Combinatorics · Mathematics 2026-03-31 Patrick Chervet , Roland Grappe , Mathieu Vallée

We determine the decomposition numbers of the partition algebra when the characteristic of the ground field is zero or larger than the degree of the partition algebra. This will allow us to determine for which exact values of the parameter…

Representation Theory · Mathematics 2014-03-21 Armin Shalile

We study the cohomology of parabolic Deligne-Lusztig varieties associated to unipotent blocks of GLn(q). We show that the geometric version of Brou\'e's conjecture over Q_\ell, together with Craven's formula, holds for any unipotent block…

Representation Theory · Mathematics 2011-12-23 Olivier Dudas

To follow up on the results of [1], we propose a computationally efficient explicit cyclic decomposition of the maximal tori in the groups $SL_n(q)$ and $SU_n(q)$ and their projective images. We also derive some corollaries to simplify…

Group Theory · Mathematics 2019-08-08 Andrei V. Zavarnitsine

This paper has two main parts. Firstly, we give a classification of the $\ell$-blocks of finite special linear and unitary groups $SL_n(\epsilon q)$ in the non-defining characteristic $\ell\ge 3$. Secondly, we describe how the…

Representation Theory · Mathematics 2019-01-18 Zhicheng Feng

The symplectic blob algebra is a physically motivated quotient of the Hecke algebra $H(\tilde{C}_n)$ with a diagram calculus. We find the blocks for the symplectic blob algebra for all specialisations of its parameters over the complex…

Representation Theory · Mathematics 2024-07-11 Oliver H. King , Paul P. Martin , Alison E. Parker

Let $R$ be a finite commutative ring with identity and $U(R)$ be its group of units. In 2005, El-Kassar and Chehade presented a ring structure for $U(R)$ and as a consequence they generalized this group of units to the generalized group of…

Group Theory · Mathematics 2021-01-05 Therrar Kadri , Mohammad El-Hindi

Let ${\mathbb{G}}$ be a simply connected ${\mathbb{Z}}_\ell$-spets, let $q$ be a prime power, prime to $\ell$ and let $S$ be the underlying Sylow $\ell$-subgroup. Firstly, motivated by known formulae for values of Deligne-Lusztig characters…

Representation Theory · Mathematics 2025-07-14 Radha Kessar , Gunter Malle , Jason Semeraro

We study the mod $\ell$ Weil representation of a finite unitary group and related Deligne--Lusztig inductions. In particular, we study their decomposition as representations of a symplectic group, and give a construction of a mod $\ell$…

Representation Theory · Mathematics 2025-02-25 Naoki Imai , Takahiro Tsushima

We prove the decomposition conjecture of Leclerc and Thibon for the Schur algebra. We also give a new approach to the Lusztig conjecture for the dimension of the simple U(sl_k)-modules at roots of unity via canonical bases of the Hall…

Quantum Algebra · Mathematics 2007-05-23 Michela Varagnolo , Eric Vasserot

Let $F$ be a non-archimedean local field and $G$ the $F$-points of a connected simply-connected reductive group over $F$. In this paper, we study the unipotent $\ell$-blocks of $G$, for $\ell \neq p$. To that end, we introduce the notion of…

Representation Theory · Mathematics 2023-09-13 Thomas Lanard

In this article we give examples which show that the TQFT representations of the mapping class groups derived from quantum SU(N) for N>2 are generically decomposable. One general decomposition of the representations is induced by the…

Geometric Topology · Mathematics 2007-06-27 Qi Chen , Thomas Kerler

The decomposition matrix of a finite group in prime characteristic p records the multiplicities of its p-modular irreducible representations as composition factors of the reductions modulo p of its irreducible representations in…

Representation Theory · Mathematics 2014-10-21 Eugenio Giannelli , Mark Wildon