English
Related papers

Related papers: Cycles on splitting models of Shimura varieties

200 papers

Let $K$ be a complete discrete valuation field. Let $\mathcal{O}_K$ be its ring of integers. Let $k$ be its residue field which we assume to be algebraically closed of characteristic exponent $p\geq1$. Let $G/K$ be a semi-abelian variety.…

Algebraic Geometry · Mathematics 2016-02-26 Alan Hertgen

In this paper, we study the basic locus in the fiber at $p$ of a certain unitary Shimura variety with a certain parahoric level structure. The basic locus $\widehat{\mathcal{M}^{ss}}$ is uniformized by a formal scheme $\mathcal{N}$ which is…

Number Theory · Mathematics 2018-07-27 Sungyoon Cho

We formulate a detailed conjectural Eichler-Shimura type formula for the cohomology of local systems on a Picard modular surface associated to the group of unitary similitudes $\mathrm{GU}(2,1,\mathbb{Q}(\sqrt{-3}))$. The formula is based…

Algebraic Geometry · Mathematics 2020-12-15 Jonas Bergström , Gerard van der Geer

We construct projective toroidal compactifications for integral models of Shimura varieties of Hodge type. We also construct integral models of the minimal (Satake-Baily-Borel) compactification. Our results essentially reduce the problem to…

Number Theory · Mathematics 2018-03-13 Keerthi Madapusi Pera

In this paper, we study special cycles on the Kr\"amer model of $\mathrm{U}(1,1)(F/F_0)$-Rapoport-Zink spaces where $F/F_0$ is a ramified quadratic extension of $p$-adic number fields with the assumption that the $2$-dimensional hermitian…

Algebraic Geometry · Mathematics 2022-02-07 Yousheng Shi

We construct a family of special cycle classes on the regular integral model of an orthogonal Shimura variety, and show that these cycle classes appear as Fourier coefficients of a Siegel modular form. Passing to the generic fiber of the…

Number Theory · Mathematics 2025-11-03 Benjamin Howard , Keerthi Madapusi

This survey article explains the construction of Rapoport-Zink local models and their use in understanding various questions relating to the singularities in the reduction modulo p of certain Shimura varieties with parahoric level structure…

Algebraic Geometry · Mathematics 2007-05-23 Thomas J. Haines

Kottwitz's conjecture describes the contribution of a supercuspidal represention to the cohomology of a local Shimura variety in terms of the local Langlands correspondence. A natural extension of this conjecture concerns Scholze's more…

Number Theory · Mathematics 2022-03-21 Tasho Kaletha , David Hansen , Jared Weinstein

We survey the theory of local models of Shimura varieties. In particular, we discuss their definition and illustrate it by examples. We give an overview of the results on their geometry and combinatorics obtained in the last 15 years. We…

Algebraic Geometry · Mathematics 2011-08-30 G. Pappas , M. Rapoport , B. Smithling

The aim of this article is the construction of the interior motive of a Picard variety. Those are Shimura varieties of PEL type. Our result is an application of the strategy developed by Wildeshaus to construct a Hecke-invariant motive…

Algebraic Geometry · Mathematics 2017-05-10 Guillaume Cloître

We prove the Scholze--Weinstein conjecture on the existence and uniqueness of local models for local Shimura varieties, as well as the test function conjecture of Haines--Kottwitz in this framework. To this end, we establish a…

Algebraic Geometry · Mathematics 2026-02-03 Johannes Anschütz , Ian Gleason , João Lourenço , Timo Richarz

In this largely expository note, we explain some recent progress on new cycles on Shimura varieties and Rapoport-Zink spaces, (twisted) arithmetic fundamental lemma, and arithmetic analogs of relative Langlands program. We explain related…

Number Theory · Mathematics 2025-05-13 Zhiyu Zhang

We show that local-global compatibility (at split primes) away from $p$ holds at all points of the $p$-adic eigenvariety of a definite $n$-variable unitary group. The novelty is we allow non-classical points, possibly non-\'{e}tale over…

Number Theory · Mathematics 2017-08-04 Christian Johansson , James Newton , Claus Sorensen

We establish a connection between the representation theory of certain noncommutative singular varieties and two-dimensional lattice models. Specifically, we consider noncommutative biparametric deformations of the fiber product of two…

Representation Theory · Mathematics 2020-06-09 Jonas T. Hartwig

We study the six-dimensional solvmanifolds that admit complex structures of splitting type classifying the underlying solvable Lie algebras. In particular, many complex structures of this type exist on the Nakamura manifold $X$, and they…

Differential Geometry · Mathematics 2017-12-12 Daniele Angella , Antonio Otal , Luis Ugarte , Raquel Villacampa

The global geometric Langlands correspondence relates Hecke eigensheaves on the moduli stack of G-bundles on a smooth projective algebraic curve X and holomorphic G'-bundles with connection on X, where G' is the Langlands dual group of G.…

Quantum Algebra · Mathematics 2007-05-23 Edward Frenkel

In 1979, Lusztig proposed a cohomological construction of supercuspidal representations of reductive $p$-adic groups, analogous to Deligne-Lusztig theory for finite reductive groups. In this paper we establish a new instance of Lusztig's…

Representation Theory · Mathematics 2015-07-27 Charlotte Chan

We define modular equations in the setting of PEL Shimura varieties as equations describing Hecke correspondences, and prove upper bounds on their degrees and heights. This extends known results about elliptic modular polynomials, and…

Algebraic Geometry · Mathematics 2022-03-09 Jean Kieffer

This is a largely expository article based on our previous work on arithmetic diagonal cycles on unitary Shimura varieties. We define a class of Shimura varieties closely related to unitary groups which represent a moduli problem of abelian…

Number Theory · Mathematics 2020-08-27 Michael Rapoport , Brian Smithling , Wei Zhang

We construct a new family of mod $p$ weight shifting differential operators on Hodge type Shimura varieties at hyperspecial level. First we construct basic theta operators, labelled by positive roots, that generalize Katz's theta operator…

Number Theory · Mathematics 2026-01-19 Martin Ortiz