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Related papers: Basic Loci of Positive Coxeter Type for $GL_n$

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In this work, we study the supersingular locus of the Shimura variety associated to the unitary group $\mathrm{GU}(2,4)$ over a ramified prime. We show that the associated Rapoport-Zink space is flat, and we give an explicit description of…

Number Theory · Mathematics 2023-09-21 Stefania Trentin

Bounded local G-shtukas are function field analogs for p-divisible groups with extra structure. We describe their deformations and moduli spaces. The latter are analogous to Rapoport-Zink spaces for p-divisible groups. The underlying…

Algebraic Geometry · Mathematics 2014-01-28 U. Hartl , E. Viehmann

We define and give axioms for Garside and locally Garside categories. We give an application to Coxeter and Artin groups and Deligne-Lusztig varieties.

Group Theory · Mathematics 2007-05-23 François Digne , Jean Michel

We construct the Bruhat--Tits stratification of the reduced locus of the ramified unitary Rapoport--Zink space of signature $(n-1,1)$, with the level being the stabilizer of a vertex lattice. We develop the local model theory for…

Algebraic Geometry · Mathematics 2026-05-12 Qiao He , Yu Luo , Yousheng Shi

Class polynomials attached to affine Hecke algebras were first introduced by X.~He in \cite{He1}. They play an important role in the study of affine Deligne-Lusztig varieties. Motivated by \cite{He2}, we compute the class polynomials…

Representation Theory · Mathematics 2014-09-17 Zhongwei Yang

This paper studies affine Deligne-Lusztig varieties $X_{\tw}(b)$ in the affine flag variety of a quasi-split tamely ramified group. We describe the geometric structure of $X_{\tw}(b)$ for a minimal length element $\tw$ in the conjugacy…

Algebraic Geometry · Mathematics 2013-09-11 Xuhua He

In this notes, we will give an exposition of some results on the method of partial conjugation action. We first discuss the partial conjugation action of a parabolic subgroup of a Coxeter group. We then discuss some applications to…

Representation Theory · Mathematics 2011-10-11 Chuying Fang , Xuhua He

In this article we study the cohomology of deep level Deligne--Lusztig varieties of Coxeter type, attached to a reductive group over a local non-archimedean field, which splits over an unramified extension. This allows to construct some new…

Representation Theory · Mathematics 2024-12-10 Alexander B. Ivanov , Sian Nie , Panjun Tan

We analyze the geometry of some $p$-adic Deligne--Lusztig spaces $X_w(b)$ introduced in [Iva21] attached to an unramified reductive group ${\bf G}$ over a non-archimedean local field. We prove that when ${\bf G}$ is classical, $b$ basic and…

Algebraic Geometry · Mathematics 2026-05-27 Alexander B. Ivanov

In 1976, Deligne and Lusztig realized the representation theory of finite groups of Lie type inside \'etale cohomology of certain algebraic varieties. Recently, a $p$-adic version of this theory started to emerge: there are $p$-adic…

Representation Theory · Mathematics 2024-10-10 Jakub Löwit

The study of affine Deligne-Lusztig varieties originally arose from arithmetic geometry, but many problems on affine Deligne-Lusztig varieties are purely Lie-theoretic in nature. This survey deals with recent progress on several important…

Algebraic Geometry · Mathematics 2018-07-11 Xuhua He

In this paper, we consider affine Deligne-Lusztig varieties $X_w(b)$ and their certain union $X(\mu,b)$ inside the affine flag variety of a reductive group. Several important results in the study of affine Deligne-Lusztig varieties have…

Representation Theory · Mathematics 2021-10-06 Arghya Sadhukhan

In this paper, we discuss some partitions of affine flag varieties. These partitions include as special cases the partition of affine flag variety into affine Deligne-Lusztig varieties and the affine analogue of the partition of flag…

Representation Theory · Mathematics 2009-10-28 Xuhua He

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

This article is the final one of a series of articles on certain blocks of modular representations of finite groups of Lie type and the associated geometry. We prove the conjecture of Brou\'e on derived equivalences induced by the complex…

Representation Theory · Mathematics 2012-04-10 Olivier Dudas , Raphaël Rouquier

We classify a natural collection of GL(2,R)-invariant subvarieties, which includes loci of double covers, the orbits of the Eierlegende-Wollmilchsau, Ornithorynque, and Matheus-Yoccoz surfaces, and loci appearing naturally in the study of…

Dynamical Systems · Mathematics 2022-05-24 Paul Apisa , Alex Wright

We determine the Galois representations inside the $l$-adic cohomology of some quaternionic and related unitary Shimura varieties at ramified places. The main results generalize the previous works of Reimann and Kottwitz in this setting to…

Number Theory · Mathematics 2019-02-20 Xu Shen

We provide a stratification of the $\mathrm{AGL}_r(\mathbb{C})$-representation variety of the fundamental group of the complement of a twisted Hopf link in terms of a stratification of the corresponding…

Geometric Topology · Mathematics 2026-05-14 Ángel Molina-Navarro

We study the cohomology of various local Shimura varieties for $GL_n$. This provides an explicit description of the spectral action constructed by Fargues-Scholze in certain cases and allows us to prove some strongly generic part of the…

Number Theory · Mathematics 2025-05-19 Kieu Hieu Nguyen

We give a purely combinatorial proof of the positivity of the stabilized forms of the generalized exponents associated to each classical root system. In finite type A_{n-1}, we rederive the description of the generalized exponents in terms…

Representation Theory · Mathematics 2018-01-03 Cedric Lecouvey , Cristian Lenart