This is a ZJU-Westlake(浙大-西湖大学) joint seminar on Algebraic and Arithmetic Geometry. The seminar will meet at 3:00–4:00 pm, Tuesday weekly and alternatively in Zijingang, Zhejiang University or Yungu, Westlake University.

Here are the precise locations:

ZJU Location: Room 206, Hai Na Yuan #2, Zijingang Campus （海纳苑2幢206室，浙大紫金港校区）

Westlake Location: E14-215, Yungu Campus (云谷校区E14楼215室)

If you would like to attend the seminar and want to get entrance to Zijingang Campus (resp. Yungu Campus), please contact leiwu23@zju.edu.cn (resp. zhaoyigeng@westlake.edu.cn)

Click on a title to reveal its abstract.

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Schedule (Fall 2026)

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Sep 15 at ZJU

• Speaker: Dingxin Zhang 张鼎新 (SIMIS,Shanghai)
• Title: Cohomological Divisibility of Exponential Sums
• Using the theory of the sheaf-theoretic Mellin transform of Gabber–Loeser, we prove that the Adolphson–Sperber p-adic bound for exponential sums holds for every individual ℓ-adic Frobenius eigenvalue attached to an exponential sum over F_q, uniformly for all ℓ not dividing q.

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Sep 22 at ZJU

• Speaker: Jingren Chi 迟敬人 (MCM,AMSS)
• Title: Reductive monoids over general base
• We report on a theory of affine algebraic monoids over general base schemes whose unit groups are reductive. Our main result is a classification theorem for such objects, generalizing works of Vinberg and Rittatore over a field. As applications, we establish a Steinberg-type theorem on adjoint quotients of reductive monoids over general base schemes, and construct finite type integral models of the Vinberg monoids. A main tool in our construction is Lusztig's theory of modified quantum groups and canonical bases. This is joint work with Simon Jacques.

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Sep 29 at Westlake
• Speaker: Qianyu Chen 陈钱钰
• Title: Filtrations on local cohomology and Injectivity theorems
• Local cohomology modules were introduced by Grothendieck in algebraic geometry. There are two filtrations on local cohomology modules of different nature: the Hodge filtration and the Ext filtration. In this talk, I will discuss a result that the Hodge filtration is contained Ext filtration, which answers a question of Mustata and Popa. Using the same idea, we can also resolve the injectivity conjecture of Popa-Shen-Vo. This is joint work with Sebastian Olano and Brad Dirks.

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Oct 13 at Westlake
• Speaker: Ruiran Sun 孙锐然 (Xiamen University)
• Title: TBD

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Oct 20 at ZJU
• Speaker: Fei Si 司飞 (Xi'an Jiaotong University)
• Title: TBD

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Oct 27 at Westlake
• Speaker: Shizhang Li 李时璋 (MCM,AMSS)
• Title: TBD

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Nov 3 at ZJU
• Speaker: Zijun Zhou 周子浚 (Shanghai Jiao Tong University)
• Title: TBD

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Nov 10 at Westlake
• Speaker: Yupeng Wang 王宇鹏 (SCMS, Fudan University)
• Title: TBD

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Nov 17 at ZJU
• Speaker: Yichen Qin 秦翊宸 (Fudan University)
• Title: TBD

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Nov 24 at Westlake
• Speaker: TBD
• Title: TBD

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Dec 1 at ZJU
• Speaker: Yiwen Ding 丁一文 (BICMR, Peking University)
• Title: TBD

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Dec 8 at Westlake
• Speaker: TBD
• Title: TBD

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Dec 15 at ZJU
• Speaker: TBD
• Title: TBD

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Dec 22 at Westlake
• Speaker: TBD
• Title: TBD

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Dec 29 at ZJU
• Speaker: Zhiyu Tian 田志宇 (BICMR, Peking University)
• Title: TBD

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