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This is the last of three papers on Drinfeld presentations of quasi-split affine iquantum groups $\widetilde{{\mathbf U}}^\imath$, settling the remaining type ${\rm AIII}^{(\tau)}_{2r}$. This type distinguishes itself among all quasi-split…

Representation Theory · Mathematics 2025-11-04 Ming Lu , Xiaolong Pan , Weiqiang Wang , Weinan Zhang

The Divisibility Graph of a finite group $G$ has vertex set the set of conjugacy class lengths of non-central elements in $G$ and two vertices are connected by an edge if one divides the other. We determine the connected components of the…

Group Theory · Mathematics 2016-12-15 Adeleh Abdolghafourian , Mohammad A. Iranmanesh , Alice C. Niemeyer

The analysis and the classification of all reductions for the nonlinear evolution equations solvable by the inverse scattering method is an interesting and still open problem. We show how the second order reductions of the N-wave…

Exactly Solvable and Integrable Systems · Physics 2009-10-31 V. S. Gerdjikov , G. G. Grahovski , N. A. Kostov

We consider the closure space on the set of strings of a gentle algebra of finite representation type. Palu, Pilaud, and Plamondon proved that the collection of all biclosed sets of strings forms a lattice, and moreover, that this lattice…

Representation Theory · Mathematics 2018-08-31 Alexander Garver , Thomas McConville , Kaveh Mousavand

We study (strictly) join irreducible varieties in the lattice of subvarieties of residuated lattices. We explore the connections with well-connected algebras and suitable generalizations, focusing in particular on representable varieties.…

Logic · Mathematics 2021-05-31 Paolo Aglianò , Sara Ugolini

In this note, we give two different proofs that relation algebra $52_{65}$ is representable over a finite set. The first is probabilistic, and uses Johnson schemes. The second is an explicit group representation over $…

Logic · Mathematics 2017-12-04 Jeremy F. Alm , Roger D. Maddux

We prove a weak version of Lusztig's conjecture on explicit description of the asymptotic Hecke algebras (both finite and affine), and explain its relation to Lusztig's classification of character sheaves.

Representation Theory · Mathematics 2007-10-29 Roman Bezrukavnikov , Michael Finkelberg , Victor Ostrik

We give a survey on the theory of representation-finite and certain minimal representation-infinite algebras.The main goals are the existence of multiplicative bases and of coverings with good properties. Both are attained via…

Representation Theory · Mathematics 2013-02-06 Klaus Bongartz

In the study of lattice walks there are several examples of enumerative equivalences which amount to a trade-off between domain and endpoint constraints. We present a family of such bijections for simple walks in Weyl chambers which use arc…

Combinatorics · Mathematics 2018-05-22 Julien Courtiel , Éric Fusy , Mathias Lepoutre , Marni Mishna

Let $\Gamma$ be a finitely generated group and $G$ be a noncompact semisimple connected real Lie group with finite center. We consider the space $\mathcal X$ of conjugacy classes of reductive representations of $\Gamma$ into $G$. We define…

Differential Geometry · Mathematics 2011-09-28 Anne Parreau

The theory of almost characters which is closely related to character sheaves is proposed by Lusztig to study the representation theory of finite reductive groups. In this article we show that the decomposition of the Weil character for…

Representation Theory · Mathematics 2022-08-03 Shu-Yen Pan

In this paper we study some algebraic properties of the rack structure as well as the representation theory of it, following the ideas given by M. Elhamdadi and E. M. Moutuou in \cite{Elhamdadi}. We establish a correspondence between the…

The purpose of this paper is to explore the concept of localization, which comes from homotopy theory, in the context of finite simple groups. We give an easy criterion for a finite simple group to be a localization of some simple subgroup…

Group Theory · Mathematics 2007-05-23 Jose L. Rodriguez , Jerome Scherer , Jacques Thevenaz

Let G be a connected reductive group. We define a map from the set of unipotent classes in G to the set of conjugacy classes in the Weyl group (assuming that the characteristic is not bad). This map is a one sided inverse of a map in the…

Representation Theory · Mathematics 2010-08-17 G. Lusztig

We recall some classical results relating normality and some natural weakenings of normality in $\Psi$-spaces over almost disjoint families of branches in the Cantor tree to special sets of reals like $Q$-sets, $\lambda$-sets and…

General Topology · Mathematics 2021-12-21 Vinicius Rodrigues , Victor dos Santos Ronchim , Paul Szeptycki

We show that a compact representation of a semisimple Lie group has an orthogonal decomposition into finite length representations. This generalises and simplifies a number of more special spectral theorems in the literature. We apply it to…

Number Theory · Mathematics 2024-01-30 Anton Deitmar

Given a stratified variety X with strata satisfying a cohomological parity-vanishing condition, we define and show the uniqueness of "parity sheaves", which are objects in the constructible derived category of sheaves with coefficients in…

Representation Theory · Mathematics 2016-03-31 Daniel Juteau , Carl Mautner , Geordie Williamson

In a previous paper I have defined a new basis for the representation ring of a Weyl group. In this paper we show that the new basis is related to the standard basis by an upper triangular unipotent matrix. We also give a new…

Representation Theory · Mathematics 2019-07-09 G. Lusztig

We study Coxeter diagrams of some unitary reflection groups. Using solely the combinatorics of diagrams, we give a new proof of the classification of root lattices defined over $\cE = \ZZ[e^{2 \pi i/3}]$: there are only four such lattices,…

Group Theory · Mathematics 2010-12-07 Tathagata Basak

Let G be a connected reductive algebraic group over an algebraically closed field k. We consider the strata in G defined by Lusztig as fibers of a map given in terms truncated induction of Springer representations. We extend to arbitrary…

Representation Theory · Mathematics 2020-03-13 Giovanna Carnovale