Speaker：Felix Schremmer (The University of Hong Kong)

Time：2026-3-5 14:30

Location：Conference Room S204 at Experiment Building at Haiyun Campus

Abstract:

Shimura varieties play a central role in the Langlands program. In many arithmetic applications, one studies their integral models, which are typically constructed from moduli spaces of abelian varieties with extra structure. These are matched with certain simpler schemes, known as local models. In a joint work with Xuhua He and Qingchao Yu, we prove the Cohen-Macaulayness property of all local models by solving a conjecture of Görtz. This implies the same property for most integral models studied in the literature. Our approach relies on a careful analysis of the special fibre, which treats all root systems and residue characteristics uniformly.