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Related papers: On affine Lusztig varieties

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We classify affine varieties with an action of a connected, reductive algebraic group such that the group is isomorphic to an open orbit in the variety. This is accomplished by associating a set of one-parameter subgroups of the group to…

Algebraic Geometry · Mathematics 2010-12-20 David Murphy

We prove that for extended Dynkin quivers, simple perverse sheaves in Lusztig category are characterized by the nilpotency of their singular support. This proves a conjecture of Lusztig in the case of affine quivers. For cyclic quivers, we…

Algebraic Geometry · Mathematics 2025-02-10 Lucien Hennecart

It is well-known that affine Hecke algebras are very useful to describe the smooth representations of any connected reductive p-adic group G, in terms of the supercuspidal representations of its Levi subgroups. The goal of this paper is to…

Representation Theory · Mathematics 2024-08-13 Anne-Marie Aubert , Ahmed Moussaoui , Maarten Solleveld

We determine the set of connected components of closed affine Deligne-Lusztig varieties for hyperspecial maximal parahoric subgroups of unramified connected reductive groups. This extends the work by Viehmann for split reductive groups, and…

Algebraic Geometry · Mathematics 2015-11-17 Sian Nie

Let $\mathfrak{g}$ be a simple finite dimensional complex Lie algebra and let $\widehat{\mathfrak{g}}$ be the corresponding affine Lie algebra. Kac and Wakimoto observed that in some cases the coefficients in the character formula for a…

Representation Theory · Mathematics 2024-03-28 Roman Bezrukavnikov , Victor Kac , Vasily Krylov

The aim of this paper is to give a new explicit construction of Lusztig's asymptotic algebra in affine type $\mathsf{A}$. To do so, we construct a balanced system of cell modules, prove an asymptotic version of the Plancherel Theorem and…

Representation Theory · Mathematics 2026-03-24 Nathan Chapelier-Laget , Jérémie Guilhot , Eloise Little , James Parkinson

We will construct the Lusztig form for the quantum loop algebra of $\mathfrak{gl}_n$ by proving the conjecture \cite[3.8.6]{DDF} and establish partially the Schur--Weyl duality at the integral level in this case. We will also investigate…

Quantum Algebra · Mathematics 2014-04-24 Jie Du , Qiang Fu

Answering a question of Kuniba, Misra, Okado, Takagi, and Uchiyama, it is shown that certain Demazure characters of affine type A, coincide with the graded characters of coordinate rings of closures of conjugacy classes of nilpotent…

Quantum Algebra · Mathematics 2007-05-23 Mark Shimozono

Rapoport and Kottwitz defined the affine Deligne-Lusztig varieties $X_{\tilde{w}}^P(b\sigma)$ of a quasisplit connected reductive group $G$ over $F = \mathbb{F}_q((t))$ for a parahoric subgroup $P$. They asked which pairs $(b, \tilde{w})$…

Representation Theory · Mathematics 2007-05-23 Daniel C. Reuman

To any element of a connected, simply connected, semisimple complex algebraic group G and a choice of an element of the corresponding Weyl group there is an associated Lusztig variety. When the element of G is regular semisimple, the…

Algebraic Geometry · Mathematics 2022-06-13 Alex Abreu , Antonio Nigro

For a possibly twisted loop group $LG$, and any character sheaf of its Iwahori subgroup, we identify the associated affine Hecke category with a combinatorial category of Soergel bimodules. In fact, we prove such results for affine Hecke…

Representation Theory · Mathematics 2025-07-23 Gurbir Dhillon , Yau Wing Li , Zhiwei Yun , Xinwen Zhu

Let $H$ be a generic affine Hecke algebra (Iwahori-Matsumoto definition) over a polynomial algebra with a finite number of indeterminates over the ring of integers. We prove the existence of an integral Bernstein-Lusztig basis related to…

Representation Theory · Mathematics 2007-05-23 Marie-France Vigneras

We examine the set of $J_b(F)$-orbits in the set of irreducible components of affine Deligne-Lusztig varieties for a hyperspecial subgroup and minuscule coweight $\mu$. Our description implies in particular that its number of elements is…

Algebraic Geometry · Mathematics 2019-03-15 Paul Hamacher , Eva Viehmann

We address two fundamental questions in the representation theory of affine Hecke algebras of classical types. One is an inductive algorithm to compute characters of tempered modules, and the other is the determination of the constants in…

Representation Theory · Mathematics 2013-11-12 Dan Ciubotaru , Midori Kato , Syu Kato

Under some technical assumptions, and building on joint work with Bezrukavnikov, we prove a multiplicity formula for indecomposable tilting perverse sheaves on affine flag varieties, with coefficients in a field of characteristic $p$, in…

Representation Theory · Mathematics 2025-09-16 Simon Riche

Let $H$ be the Iwahori-Hecke algebra and let $J$ be Lusztig's asymptotic Hecke algebra, both specialized to type $\tilde{A}_1$. For $\mathrm{SL}_2$, when the parameter $q$ is specialized to a prime power, Braverman and Kazhdan showed…

Representation Theory · Mathematics 2021-12-01 Stefan Dawydiak

We study a family of affine varieties arising from a version of an old problem due to Birkhoff asking for the classification of embeddings of finite abelian p-groups. We show that all of these varieties are irreducible and have a dense…

Representation Theory · Mathematics 2018-10-31 Grzegorz Bobinski

We define Kazhdan-Lusztig bases and study asymptotic forms for affine $q$-Schur algebras following Du and McGerty. We will show that the analogues of Lusztig's conjectures for Hecke algebras with unequal parameters hold for affine $q$-Schur…

Representation Theory · Mathematics 2014-08-01 Weideng Cui

Affine Hecke algebras arise naturally in the study of smooth representations of reductive $p$-adic groups. Finite dimensional complex representations of affine Hecke algebras (under some restriction on the isogeny class and the parameter…

Representation Theory · Mathematics 2014-07-01 Xuhua He

We first describe how the Kashiwara involution on crystals of affine type $A$ is encoded by the combinatorics of aperiodic multisegments. This yields a simple relation between this involution and the Zelevinsky involution on the set of…

Representation Theory · Mathematics 2009-04-22 Nicolas Jacon , Cédric Lecouvey
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