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Related papers: Local models for ramified unitary groups

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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

In this article we study motives corresponding to the moduli stacks of G-shtukas and their local models. In particular we deal with the question of describing their motivic fundamental invariants. As an application, we provide a criterion…

Number Theory · Mathematics 2020-12-22 Esmail Arasteh Rad , Somayeh Habibi

We describe a model-theoretic setting for the study of Shimura varieties, and study the interaction between model theory and arithmetic geometry in this setting. In particular, we show that the model-theoretic statement of a certain…

Logic · Mathematics 2015-10-07 Christopher Daw , Adam Harris

We prove a fixed point theorem for the action of certain local monodromy groups on \'etale covers and use it to deduce lower bounds in essential dimension. In particular, we give more geometric proofs of many (but not all) of the results of…

Algebraic Geometry · Mathematics 2020-07-21 Patrick Brosnan , Najmuddin Fakhruddin

We study the locus of abelian Galois covers of $\mathbb{P}^{1}$ in $A_{g}$ and the problem of occurrence of Shimura (special) subvarieties generated by these covers in the Torelli locus $T_{g}$ inside $A_{g}$. We first investigate the…

Algebraic Geometry · Mathematics 2015-08-20 Abolfazl Mohajer , Kang Zuo

We determine the type of the zeta functions and the range of the dimensions of the moduli spaces of finite flat models of two-dimensional local Galois representations over finite fields. This gives a generalization of Raynaud's theorem on…

Number Theory · Mathematics 2020-11-24 Naoki Imai

Let G be the unramified unitary group in three variables defined over a p-adic field F of odd residual characteristic. In this paper, we investigate local newforms for irreducible admissible representations of G. We introduce a family of…

Representation Theory · Mathematics 2011-06-29 Michitaka Miyauchi

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

We study integral models of some Shimura varieties with bad reduction at a prime $p$, namely the Siegel modular variety and Shimura varieties associated with some unitary groups. We focus on the case where the level structure at $p$ is…

Algebraic Geometry · Mathematics 2025-10-15 Giulio Marazza

We use the Taylor-Wiles-Kisin patching method to investigate the multiplicities with which Hecke eigensystems appear in the mod-$\ell$ cohomology of unitary Shimura sets, associated to central simple algebras of the form $B=M_2(D)$, for $D$…

Number Theory · Mathematics 2024-10-14 Jeffrey Manning

This paper studies graded manifolds with local coordinates concentrated in non-negative degrees. We provide a canonical description of these objects in terms of classical geometric data and, building on this geometric viewpoint, we prove…

Differential Geometry · Mathematics 2024-09-04 Henrique Bursztyn , Miquel Cueca , Rajan Amit Mehta

We survey some recent work on the geometric Satake of p-adic groups and its applications to some arithmetic problems of Shimura varieties. We reformulate a few constructions appeared in the previous works more conceptually.

Algebraic Geometry · Mathematics 2018-10-18 Xinwen Zhu

The common behaviour of many families of numerical semigroups led up to defining, firstly, the Frobenius varieties and, secondly, the (Frobenius) pseudo-varieties. However, some interesting families are still out of these definitions. To…

Group Theory · Mathematics 2018-12-04 Aureliano M. Robles-Pérez , José Carlos Rosales

We list combinatorial criteria of some singularities, which appear in the Minimal Model Program or in the study of (singular) Fano varieties, for spherical varieties. Most of the results of this paper are already known or are quite easy…

Algebraic Geometry · Mathematics 2015-10-15 Boris Pasquier

Using the work of Fargues-Scholze, we prove a vanishing theorem for the generic unramified part of the cohomology of local Shimura varieties of general linear groups. This gives an alternative approach to vanishing results of…

Number Theory · Mathematics 2021-06-22 Teruhisa Koshikawa

Consider a family f:A --> U of g-dimensional abelian varieties over a quasiprojective manifold U. Suppose that the induced map from U to the moduli scheme of polarized abelian varieties is generically finite and that there is a projective…

Algebraic Geometry · Mathematics 2009-10-12 Martin Moeller , Eckart Viehweg , Kang Zuo

The special fiber of the local model of a PEL Shimura variety with Iwahori-type level structure admits a cellular decomposition. The set of strata is in a natural way a finite subset of the affine Weyl group determined by the Shimura data.…

Representation Theory · Mathematics 2007-05-23 T. Haines , B. C. Ngo

We prove the existence of good smooth integral models of Shimura varieties of Hodge type in arbitrary unramified mixed characteristic $(0,p)$. As a first application we provide a smooth solution (answer) to a conjecture (question) of…

Number Theory · Mathematics 2023-04-27 Adrian Vasiu

We examine the local geometry of affine surfaces which are locally symmetric. There are 6 non-isomorphic local geometries. We realize these examples as Type A, Type B, and Type C geometries using a result of Opozda and classify the relevant…

Differential Geometry · Mathematics 2017-06-19 D. D'Ascanio , P. Gilkey , P. Pisani

We present a general and comprehensive overview of recent developments in the theory of integral models of Shimura varieties of Hodge type. The paper covers the following topics: construction of integral models, their possible moduli…

Number Theory · Mathematics 2008-08-12 Adrian Vasiu