English
Related papers

Related papers: On Lusztig's conjecture for connected and disconne…

200 papers

We provide a new condition for an absolutely almost simple algebraic group to have good reduction with respect to a discrete valuation of the base field which is formulated in terms of the existence of maximal tori with special properties.…

Number Theory · Mathematics 2023-12-15 Vladimir I. Chernousov , Andrei S. Rapinchuk , Igor A. Rapinchuk

We prove that the finite exceptional groups $F_4(q)$, $E_7(q)_{\mathrm{ad}}$, and $E_8(q)$ have no irreducible complex characters with Frobenius-Schur indicator $-1$, and we list exactly which irreducible characters of these groups are not…

Representation Theory · Mathematics 2019-08-27 Stephen Trefethen , C. Ryan Vinroot

We show that Lusztig's conjecture on the irreducible characters of a reductive algebraic group over a field of positive characteristic is equivalent to the generic multiplicity conjecture, which gives a formula for the Jordan-H"older…

Representation Theory · Mathematics 2011-01-13 Peter Fiebig

In this paper we show that the convolution product of "almost characters" of a connected reductive group over a finite field is given by "structure constants" whose leading coefficients can be interpreted in K-theoretic terms and in…

Representation Theory · Mathematics 2007-05-23 G. Lusztig

Recently, a new conjecture on the degrees of the irreducible Brauer characters of a finite group was presented by the second author. In this paper we propose a 'local' version of this conjecture for blocks B of finite groups, giving a lower…

Group Theory · Mathematics 2007-05-23 Thorsten Holm , Wolfgang Willems

In this paper, we present a conjecture on the degree of unipotent characters in the cohomology of particular Deligne-Lusztig varieties for groups of Lie type, and derive consequences of it. These degrees are a necessary piece of data in the…

Representation Theory · Mathematics 2015-03-19 David A. Craven

Finite groups are said to be isospectral if they have the same sets of element orders. A finite nonabelian simple group $L$ is said to be almost recognizable by spectrum if every finite group isospectral to $L$ is an almost simple group…

Group Theory · Mathematics 2015-09-07 Mariya A. Grechkoseeva , Andrey V. Vasil'ev

Let D be a connected component of a reductive group over an algebraically closed field. We define a surjective map from the unipotent character sheaves on D to the set of strata of D, extending an earlier result which applied to connected…

Representation Theory · Mathematics 2023-04-19 G. Lusztig

Let $G$ be a finite group and $cd(G)$ denote the set of complex irreducible character degrees of $G$. In this paper, we prove that if $G$ is a finite group and $H$ is an almost simple group whose socle is Mathieu group such that $cd(G)…

Group Theory · Mathematics 2016-01-26 Seyed Hassan Alavi , Ashraf Daneshkhah , Ali Jafari

Let $G$ be a connected reductive algebraic group over an algebraically closed field $\mathbf{k}$, and let Lie$(G)$ be its associated Lie algebra. In his series of papers on unipotent elements in small characteristic, Lusztig defined a…

Representation Theory · Mathematics 2022-11-18 Laura Voggesberger

We investigate a beautiful conjecture of T. Wilde on character values and element orders of finite groups. We reduce it to a statement on nearly simple groups that can be checked ``prime by prime". For these groups, we show that a strong…

Representation Theory · Mathematics 2026-05-07 Gunter Malle , Gabriel Navarro , Pham Huu Tiep

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

Let G be a possibly disconnected reductive group over a finite field with Frobenius map F. The main result of this paper is that the characteristic functions af "admissible complexes" A on G such that F^*A is isomorphic to A form a basis of…

Representation Theory · Mathematics 2007-05-23 G. Lusztig

In this note, we formulate an observation that "almost all" irreducible ordinary characters of finite groups of Lie type remain irreducible when restricted to the derived subgroups. To see this, key ingredients are some asymptotic results…

Representation Theory · Mathematics 2021-07-08 Conghui Li

Let U be the quantum group associated to a Lie algebra of type A_n. The negative part U^- of U has a canonical basis B defined by Lusztig and Kashiwara, with favourable properties. We show how the spanning vectors of the cones defined by…

Quantum Algebra · Mathematics 2020-12-21 Bethany Marsh

Given a connected reductive group $\tilde{G}$ over a finite field $k$, and a semisimple $k$-automorphism $\varepsilon$ of $\tilde{G}$ of finite order, let $G$ denote the connected part of the group of $\varepsilon$-fixed points. Then there…

Representation Theory · Mathematics 2016-08-31 Jeffrey D. Adler , Michael Cassel , Joshua M. Lansky , Emma Morgan , Yifei Zhao

To each finite Coxeter system (W,S) and to each weight function L, Lusztig has defined the notions of constructible characters and of Lusztig families of W, using the so-called J-induction. Whenever L is constant, and using a general…

Representation Theory · Mathematics 2015-05-29 Cédric Bonnafé

Let G be a finite simple group of Lie type. In this paper we study characters of G that vanish at the non-semisimple elements and whose degree is equal to the order of a maximal unipotent subgroup of G. Such characters can be viewed as a…

Group Theory · Mathematics 2013-06-18 M. A. Pellegrini , A. E. Zalesski

Given a quasi-split connected reductive $\mathbb{R}$-group $G$ and a finite group $A$ acting on $G$ by $\mathbb{R}$-automorphisms that preserve an $\mathbb{R}$-pinning, we construct for each discrete $L$-parameter for $G$ a corresponding…

Representation Theory · Mathematics 2026-05-11 Tasho Kaletha , Paul Mezo

A countable, bounded degree graph is almost finite if it has a tiling with isomorphic copies of finitely many F\o lner sets, and we call it strongly almost finite, if the tiling can be randomized so that the probability that a vertex is on…

Group Theory · Mathematics 2025-09-22 Gábor Elek , Ádám Timár