Wildly ramified unitary local models for special parahorics. The odd dimensional case

Fuente: arXiv
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Main Author: Yang, Jie
Format: Preprint
Published: 2024
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author Yang, Jie
author_facet Yang, Jie
contents We construct local models for wildly ramified unitary similitude groups of odd dimension $n\geq 3$ with special parahoric level structure and signature $(n-1,1)$. We first give a lattice-theoretic description for parahoric subgroups using Bruhat-Tits theory in residue characteristic two, and apply them to define local models following the lead of Rapoport-Zink and Pappas-Rapoport. In our case, there are two conjugacy classes of special parahoric subgroups. We show that the local models are smooth for the one class and normal, Cohen-Macaulay for the other class. We also prove that they represent the v-sheaf local models of Scholze-Weinstein. Under some additional assumptions, we obtain an explicit moduli interpretation of the local models.
format Preprint
id arxiv_https___arxiv_org_abs_2406_16774
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publishDate 2024
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spellingShingle Wildly ramified unitary local models for special parahorics. The odd dimensional case
Yang, Jie
Number Theory
Algebraic Geometry
We construct local models for wildly ramified unitary similitude groups of odd dimension $n\geq 3$ with special parahoric level structure and signature $(n-1,1)$. We first give a lattice-theoretic description for parahoric subgroups using Bruhat-Tits theory in residue characteristic two, and apply them to define local models following the lead of Rapoport-Zink and Pappas-Rapoport. In our case, there are two conjugacy classes of special parahoric subgroups. We show that the local models are smooth for the one class and normal, Cohen-Macaulay for the other class. We also prove that they represent the v-sheaf local models of Scholze-Weinstein. Under some additional assumptions, we obtain an explicit moduli interpretation of the local models.
title Wildly ramified unitary local models for special parahorics. The odd dimensional case
topic Number Theory
Algebraic Geometry
url https://arxiv.org/abs/2406.16774