G-equivariance of formal models of flag varieties

TL;DR

This paper develops a framework for $ ext{G}$-equivariant formal models of flag varieties, establishing coherence of twisted differential operators and linking categories of modules to locally analytic representations.

Contribution

It introduces $ ext{G}$-equivariant arithmetic $ ext{D}$-modules on formal models of flag varieties and proves an anti-equivalence with admissible locally analytic representations.

Findings

Coherence of global sections of twisted differential operators.

Category of $ ext{G}$-equivariant modules is anti-equivalent to locally analytic representations.

Generalizes previous results for algebraic characters.

Abstract

Let $\mathbb{G}$ be a split connected reductive group scheme over the ring of integers $\mathfrak{o}$ of a finite extension $L|\mathbb{Q}_p$ and $\lambda\in X(\mathbb{T})$ an algebraic character of a split maximal torus $\mathbb{T}\subseteq\mathbb{G}$. Let us also consider $X^{\text{rig}}$ the rigid analytic flag variety of $\mathbb{G}$ and $G=\mathbb{G}(L)$. In the first part of this paper, we introduce a family of $\lambda$-twisted differential operators on a formal model $\mathfrak{Y}$ of $X^{\text{rig}}$. We compute their global sections and we prove coherence together with several cohomological properties. In the second part, we define the category of coadmissible $G$-equivariant arithmetic $\mathcal{D}(\lambda)$-modules over the family of formal models of the rigid flag variety $X^{\text{rig}}$. We show that if $\lambda$ is such that $\lambda + \rho$ is dominant and regular ($\rho$ being the Weyl character), then the preceding category is anti-equivalent to the category of admissible locally analytic $G$-representations, with central character $\lambda$. In particular, we generalize the results of Huyghe-Patel-Strauch-Schmidt for algebraic characters (cf. [25] in the text).