题目：Witt groups
报告人: 谢恒 (中山大学)
时间： 2023-4-21 15:00-16:00
地点: 数学院425
邀请人：孙鹏
摘要: In 1937, E. Witt introduced a group structure on the set of isometry classes of quadratic forms over an arbitrary field, which is now known as the Witt group. Witt groups give rise to a very interesting cohomology theory. Similar to K-theory and Chow groups, Witt theory also has a localization sequence. However, in Witt theory pushforwards always keep track of the orientation and the relative codimension, a fact which makes computations via the localization sequence much trickier. To this day, not many computations of Witt groups of basic projective algebraic varieties have been performed. I will talk about recent development on the computations of Witt groups, and their relations to Young diagrams in representation theory, and Clifford algebras.
报告人简介：谢恒，2015年获英国华威大学博士学位，现任中山大学副教授，主要从事K理论与代数几何的理论研究。在代数簇的Witt群和Chow-Witt群的理论和应用的研究中取得一系列进展，成果发表在Advances in Mathematics、Proceedings of the London Mathematical Society、Documenta Mathematica等著名期刊杂志。
