时间:  4月17-18日

地点: 数学科学学院新楼308

组织者: 科大代数几何团队

联系人:张磊 ( zhlei18@ustc.edu.cn, 13572098164)  

Schedule

报告信息

 顾怡（苏州大学）

 题目：A generalization of trace of Abelian varieties in positive characteristic

 摘要：Given a field extension K/k, the classical Chow’s K/k-trace of an Abelian variety over K characterizes, roughly, the“maximal”Abelian subvariety defined over k. Motivated by some phenomena in characteristic-p , we will establish a certain generalization in positive characteristic that takes into account not only Abelian subvarieties, but also group subschemes that are non-reduced. We will show such a generalization arises naturally and exists under mild assumptions. This is an ongoing project joint with Yifei Chen.

 田志宇（北京大学）

 题目：A leisurely tour around the Tate conjecture

 摘要：This talk is an informal introduction to some topics centered around the Tate conjecture. We will recall the history of the conjecture, including the influences on Tate and his proof of the conjecture in some important cases, discuss some recent results, and turn to the an integral version of the conjecture in the end.

 许世坦（北京大学）

 题目1： Rationality of Brauer-Severi surface bundles over rational 3-folds

 摘要：Rationality problems for conic bundles have been well studied over surfaces. In this talk, we generalize an etale cohomology diagram from the case of conic bundles to Brauer-Severi surface bundles over rational 3-folds . We use this generalization to prove a sufficient condition for a Brauer-Severi surface bundle to be not stably Rational.

 题目2：A special Brauer-Severi surface bundle 5-fold with nontrivial unramified Brauer class.

 摘要：we construct the claimed nontrivial 3-torsion unramified Brauer class and construct suitable flat family contains this special example.