The seminar will meet at 4:00–5:00 pm, Wednesday (almost) every week during semesters, in the lecture room of IASM (East 7 Bldg, Zijingang Campus), unless otherwise noted. The seminar is organized by the NT&RT Group at Zhejiang University.

Here are the past talks.

Click on a title to reveal its abstract.

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Schedule (2025–26 Fall)

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Sep 3

• Speaker: Yihang Zhu 朱艺航 (Tsinghua University 清华大学)
• Title: Towards local Langlands–Kottwitz method
• The Langlands–Kottwitz method seeks to express Frobenius-Hecke traces on the cohomology of Shimura varieties in terms of objects in local Harmonic analysis, namely orbital and twisted orbital integrals. We present a local analogue of that, relating the cohomology of some local Shimura varieties with twisted orbital integrals. The discrete summation over Kottwitz triples in the global case is replaced by an integral over semi-simple conjugacy classes. As application, we explain a new point of view towards Rapoport's conjecture on the vanishing of certain twisted orbital integrals, which is a key ingredient in the global Langlands–Kottwitz method for a non-quasi-split prime. This is joint work with Rong Zhou.

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Sep 17

• Speaker: Alfio Fabio La Rosa (Zhejiang University 浙江大学)
• Title: Arithmetic applications of the trace formula
• A conjecture of K. Buzzard and T. Gee posits that certain properties of the infinitesimal character of the Archimedean component of an automorphic representation translate into arithmetic properties of its non-Archimedean component. In particular, it is conjectured that C-algebraic automorphic representations are C-arithmetic. All the known cases rely on the existence of geometric models for the representation in question, but many C-algebraic representations do not admit such realisations. The main purpose of this talk is to propose to investigate the conjecture through the trace formula: I will present a non-geometric proof that cuspidal automorphic representations which are regular discrete series at infinity are C-arithmetic. I will conclude by discussing how the conjecture can be reduced to the cuspidal case.

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Sep 24

• Speaker: Pol van Hoften (Zhejiang University 浙江大学)
• Title: P-adic Fourier theory in families
• Classical Fourier theory describes measures on a locally compact abelian group in terms of functions on its Pontryagin dual. In this talk, I will explain an analogous theory for (families of) p-divisible rigid analytic groups and their duals that recovers the Amice transform when applied to the open unit disk considered as multiplicative group. This is joint work with Andrew Graham and Sean Howe.

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Oct 15

• Speaker: Ruotao Yang 杨若涛 (Chinese Academy of Sciences 中国科学院)
• Title: The application of factorization method in the study of Iwahori Gaiotto conjecture
• The Gaiotto conjecture says that the category of representations of the quantum supergroup can be realized as a category of certain sheaves on the affine Grassmannian. It is the quantum version of a particular case of the relative Langlands conjecture by Ben-Zvi–Sakellaridis–Venkatesh. In this talk, we will mainly focus on the tamely ramified version of the Gaiotto conjecture, and see the application of the factorization method in its study. The talk is organized as follows: first we will review the background and explain the statement of the conjecture; then we will roughly sketch the strategy of the proof using the factorization method; if time permits, we will explain the application of the factorization method in the general relative Langlands program. The talk is based on ongoing works with Michael Finkelberg and Roman Travkin.

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Oct 22

• Speaker: Teruhisa Koshikawa 越川皓永 (Kyoto University 京都大学)
• Title:

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Oct 29

• Speaker: Masao Oi 大井雅雄 (National Taiwan University 國立臺灣大學)
• Title:

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Nov 5

• Speaker: Shih-Yu Chen 陳昰宇 (National Tsing Hua University 國立清華大學)
• Title:

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Nov 12

• Speaker: TBD ()
• Title:

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Nov 19

• Speaker: Si Ying Lee (National University of Singapore 新加坡国立大学)
• Title:

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Nov 26

• Speaker: TBD ()
• Title:

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Dec 3

• Speaker: Peihang Wu 吴沛航 (Peking University 北京大学)
• Title:

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Dec 10

• Speaker: Jiawei An 安嘉伟 (Chinese Academy of Sciences 中国科学院)
• Title:

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Dec 17

• Speaker: Fangu Chen 陈梵谷 (University of California, Berkeley)
• Title:

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Dec 24

• Speaker: Yuanyang Jiang 江元旸 (Université Paris-Saclay)
• Title:

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Dec 31

• Speaker: Tony Feng (University of California, Berkeley)
• Title:

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