-

Can we count sheaves when p = 0 ?

组织者

阿尔坦·谢什马尼 , 杨南君 , 袁北彗

演讲者

Jiaqi Fu

时间

2026年03月05日 15:00 至 16:00

地点

A7-201

线上

Zoom 638 227 8222 (BIMSA)

摘要

Donaldson–Thomas theory (DT) provides a virtual count of coherent sheaves over complex Calabi–Yau 3-folds. From the deformation-theoretic perspective, DT invariants are the shadow of derived critical locus structures. One might be tempted to extend this picture to positive characteristic. However, the Cartier isomorphism makes the situation tricky, since there are too many cycles in de Rham cohomology in the mod p case. I will talk about the notion of infinitesimal shifted symplectic forms, suggested by Toën and Robalo, and a shifted Darboux theorem based on it. We hope this work can contribute to pursuing a DT theory in positive characteristic.