Date/Time : 16 Mar 2026 15:00
Venue : S17 #05-11 (Seminar Room 5)
Speaker : Ian Gleason, National University of Singapore

We show a folklore conjecture stating that two categorical enhancements of the automorphic side of the local Langlands correspondence agree. The first enhancement appears in Fargues–Scholze’s formulation of the categorical local Langlands correspondence, and the second one appears in Zhu’s formulation. This is joint work with Hamann, Ivanov, Lourenco, Zou.

Add to calendar :

Date/Time : 02 Mar 2026 15:00
Venue : S17 #05-11 (Seminar Room 5)
Speaker : Chenji Fu, University of Bonn

Eteve computed the Genestier-Lafforgue L-parameters for depth-zero representation for a equal-characteristic local field. I will explain how to adapt his method to the setting of Fargues-Scholze. We use certain ”smoothness” and ”properness” of the stack of shtuka to reduce the question to the local Hecke stack, where we can do an explicit computation using hyperbolic localizations following the work of ALWY on central sheaves in mixed characteristic.

Add to calendar :

Date/Time : 02 Feb 2026 15:00
Venue : S17 #05-11 (Seminar Room 5)
Speaker : Yihang Zhu, Tsinghua University

The Langlands-Kottwitz method seeks to express Frobenius-Hecke traces on the cohomology of Shimura varieties in terms of objects in local harmonic analysis which enter the Arthur-Selberg trace formula, namely orbital and twisted orbital integrals. As a local analogue, we present a formula relating the cohomology of local Shimura varieties with twisted orbital integrals. This formula bridges the point-counting formula for Shimura varieties with the point-counting formula for Igusa varieties, a manifestation of the Mantovan product relation. As an application of our local formula, we explain a new categorical-Langlands-based approach towards Rapoport’s conjecture on the vanishing of certain twisted orbital integrals, which is itself a key ingredient in the global Langlands-Kottwitz method for a non-quasi-split prime. This is joint work with Rong Zhou.

Add to calendar :

Date/Time : 15 Dec 2025 15:00
Venue : S17 #05-11 (Seminar Room 5)
Speaker : Yuta Takaya, Tokyo University

In the local Langlands program, both local Shimura varieties and type theory play important roles. Although the relationship between these two approaches remains largely open, starting from the work of Yoshida and Boyarchenko-Weinstein, it has been observed that certain affinoids around CM points in Lubin-Tate spaces reflect the associated type theory. In this talk, I will introduce analogous affinoids around unramified CM points in general local Shimura varieties, and explain the relation to regular depth-zero supercuspidal representations. If time permits, I will provide an outlook on the extension to positive depth.

Add to calendar :

Date/Time : 08 Dec 2025 15:00
Venue : S17 #04-05 (Seminar Room 2)
Speaker : Yuta Takaya, Tokyo University

The relation between period integrals and L-functions, studied since the work of Hecke and Tate, has recently been reformulated by Ben-Zvi–Sakellaridis–Venkatesh as relative Langlands duality. In this talk, I will present a version of this duality, the normalized period conjecture, in the framework of the categorical local Langlands correspondence à la Fargues-Scholze. I will describe computations for the Iwasawa-Tate and Hecke periods that support this conjecture, and discuss how it leads to a relation between distinguished representations and distinguished L-parameters. This talk is based on joint work with Milton Lin.

Add to calendar :

Date/Time : 10 Nov 2025 15:00
Venue : S17 #04-05 (Seminar Room 2)
Speaker : Jhan-Cyuan Syu, National University of Singapore

Let G be a split connected reductive group over a non-archimedean local field. The categorical local Langlands conjecture (CLLC) predicts an equivalence between lisse-étale sheaves on Bun_G, the moduli stack of G-bundles on relative Fargues-Fontaine curves, and ind-coherent sheaves on Par_G, the moduli stack of l-adically continuous L-parameters. One question is to find t-structures on the automorphic side and the spectral side such that the categorical equivalence is t-exact. On the automorphic side, there is a perverse t-structure. However, the story is still mysterious on the spectral side. After localizing at certain types of L-parameters, we can say more about t-structures. In this talk, we will localize at the trivial L-parameter and compute the multiplicity of certain perverse sheaves with the help of CLLC.

Add to calendar :

Date/Time : 03 Nov 2025 15:00
Venue : S17 #04-05 (Seminar Room 2)
Speaker : Joao Lourenco, Universite Sorbonne Paris Nord

Given a reductive group $G$ over a $p$-adic field $F$ with parahoric group model $\mathcal{G}$ over the ring of integers $O$, we can consider its associated flag variety using Witt vectors on perfect $k$-algebras: this is representable by a perfect ind-scheme by a deep theorem of Bhatt-Scholze. This time, we want to study its $\mathbb{F}_p$-étale cohomology, but its behavior is linked with coherent cohomology due to the Artin-Schreier sequence. We are going to explain how the Cohen-Macaulayness of a perfect scheme relates to its perverse $\mathbb{F}_p$-sheaves. Then, we will explain a new and uniform proof of this property for Schubert varieties in the minuscule range based on inversion of adjunction. This is joint work with Robert Cass.

Add to calendar :

Date/Time : 27 Oct 2025 15:00
Venue : S17 #04-05 (Seminar Room 2)
Speaker : Joao Lourenco, Universite Sorbonne Paris Nord

The geometric Satake equivalence of Mirkovic-Vilonen identifies the monoidal category of perverse sheaves with l-adic coefficients on the Hecke stack of a split reductive group G over a Laurent series field with the monoidal category of representations of the Langlands dual of G. However, from the point of view of the Langlands program, it is also natural to consider ramified groups and their special parahoric models. With rational l-adic coefficients, ramified Satake was proved by Zhu and Richarz, exploiting semisimplicity of the category of representations. We extend these equivalences to integral and modular l-adic coefficients, via a careful study of semi-infinite orbit filtrations that allow us to bypass the lack of fusion, and a delicate analysis of fixed point group schemes. This is joint work with Achar, Richarz and Riche.

Add to calendar :

Date/Time : 13 Oct 2025 15:00
Venue : S17 #04-05 (Seminar Room 2)
Speaker : :Si Ying Lee, National University of Singapore

I will talk about constructing integral models for Hecke correspondences in both the global and local settings, using the theory of F-gauges. Using these integral models, I will explain how one can construct integral Hecke actions on coherent cohomology for compact abelian type Shimura varieties, proving a conjecture of Fakhruddin-Pilloni. This is joint work in progress with Keerthi Madapusi.

Add to calendar :