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Related papers: On the connectedness of Deligne-Lusztig varieties

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We initiate the study of affine Deligne-Lusztig varieties with arbitrarily deep level structure for general reductive groups over local fields. We prove that for GLn and its inner forms, Lusztig's semi-infinite Deligne-Lusztig construction…

Algebraic Geometry · Mathematics 2021-01-06 Charlotte Chan , Alexander B. Ivanov

We prove Rapoport's dimension conjecture for affine Deligne-Lusztig varieties for GL_h and superbasic b. From this case the general dimension formula for affine Deligne-Lusztig varieties for special maximal compact subgroups of split groups…

Algebraic Geometry · Mathematics 2007-05-23 Eva Viehmann

In the present article we define coverings of affine Deligne-Lusztig varieties attached to a connected reductive group over a local field of characteristic $p > 0$. In the case of $\GL_2$, the unramified part of the local Langlands…

Algebraic Geometry · Mathematics 2015-04-02 Alexander Ivanov

In this paper, we consider certain union $X(\mu,b)$ of affine Deligne-Lusztig varieties in the affine flag variety that arises in the study of mod-$p$ reduction of Rapoport-Zink spaces and moduli spaces of shtukas associated to a connected…

Representation Theory · Mathematics 2022-12-14 Arghya Sadhukhan

In this short note, we will show that the metric of Deligne's pairing is continous.

Algebraic Geometry · Mathematics 2007-05-23 Atsushi Moriwaki

We prove that the Deligne-Lusztig variety associated to minimal length elements in any $\d$-conjugacy class of the Weyl group is affine, which was conjectured by Orlik and Rapoport in \cite{OR}.

Representation Theory · Mathematics 2007-07-03 Xuhua He

In this paper we give for any integer l > 2 a numerical criterion ensuring the existence of a chain of length l of lines through two general points of an irreducible variety X in P^N, involving the degrees and the number of homogeneous…

Algebraic Geometry · Mathematics 2013-05-28 Simone Marchesi , Alex Massarenti

Affine Deligne-Lusztig varieties are analogs of Deligne-Lusztig varieties in the context of an affine root system. We prove a conjecture stated in the paper arXiv:0805.0045v4 by Haines, Kottwitz, Reuman, and the first named author, about…

Representation Theory · Mathematics 2010-06-14 Ulrich Goertz , Xuhua He

Let $G$ be a connected reductive algebraic group defined over an algebraic closure of a finite field and let $F : G \to G$ be an endomorphism such that $F^d$ is a Frobenius endomorphism for some $d \geq 1$. Let $P$ be a parabolic subgroup…

Group Theory · Mathematics 2008-07-07 Cédric Bonnafé , Raphaël Rouquier

In this paper we discuss the geometry of affine Deligne Lusztig varieties with very special level structure, determining their dimension and connected and irreducible components. As application, we prove the Grothendieck conjecture for…

Algebraic Geometry · Mathematics 2020-12-21 Paul Hamacher

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

We formulate a strong positivity conjecture on characters afforded by the Alvis-Curtis dual of the intersection cohomology of Deligne-Lusztig varieties. This conjecture provides a powerful tool to determine decomposition numbers of…

Representation Theory · Mathematics 2014-02-17 Olivier Dudas , Gunter Malle

In this paper we express the class of the structure sheaves of the closures of Deligne--Lusztig varieties as explicit double Grothendieck polynomials in the first Chern classes of appropriate line bundles on the ambient flag variety. This…

Algebraic Geometry · Mathematics 2022-05-17 Thomas Hudson , Dennis Peters

We study the set of connected components of certain unions of affine Deligne-Lusztig varieties arising from the study of Shimura varieties. We determine the set of connected components for basic $\s$-conjugacy classes. As an application, we…

Algebraic Geometry · Mathematics 2020-12-16 Xuhua He , Rong Zhou

We present a simple alternative viewpoint on Hodge-Newton indecomposability, illustrating its explanatory value through a uniform proof of a combinatorial identity arising from affine Deligne-Lusztig varieties with finite Coxeter part.

Number Theory · Mathematics 2026-03-10 Dong Gyu Lim

This paper studies affine Deligne-Lusztig varieties in the affine flag manifold of a split group. Among other things, it proves emptiness for certain of these varieties, relates some of them to those for Levi subgroups, extends previous…

Algebraic Geometry · Mathematics 2014-01-14 Ulrich Goertz , Thomas J. Haines , Robert E. Kottwitz , Daniel C. Reuman

A criterion is established for the transitivity of connectedness in a transfinite graph. Its proof is much shorter than a prior argument published previously for that criterion.

Combinatorics · Mathematics 2007-05-23 A. H. Zemanian

We prove several conjectures about the cohomology of Deligne-Lusztig varieties: invariance under conjugation in the braid group, behaviour with respect to translation by the full twist, parity vanishing of the cohomology for the variety…

Representation Theory · Mathematics 2018-10-23 Cédric Bonnafé , Olivier Dudas , Raphaël Rouquier

We obtain a criterion for the automorphism group of an affine toric variety to be connected in combinatorial terms and in terms of the divisor class group of the variety. The component group of the automorphism group of a non-degenerate…

Algebraic Geometry · Mathematics 2025-03-25 Veronika Kikteva

For unramified reductive groups, we determine the connected components of affine Deligne-Lusztig varieties in the partial affine flag varieties. Based on the work of Hamacher-Kim and Zhou, this result allows us to verify, in the unramified…

Algebraic Geometry · Mathematics 2021-07-23 Sian Nie