Abstract：

A cornerstone of modern mathematical physics is the deep relation between geometric structures and gauge theory. After briefly reviewing some basic aspects of Donaldson-Witten theory, we will sketch a systematic physical approach to its K-theoretic generalization. This advancement is achieved through the path integral of 5d N=1 SU(2) super Yang-Mills theory defined on X×S^1 where X is a closed, smooth four-manifold. After a partial topological twist along X, the correlation functions produce K-theoretic Donaldson invariants. For a large class of four-manifold X, we successfully evaluate the path integral using the low energy effective theory.

报告人简介：

张欣宇，浙江大学物理学院“百人计划”研究员、博士生导师。他于2017年获美国纽约州立大学石溪分校物理学博士学位，此后分别在美国罗格斯大学和德国电子同步加速器研究所从事博士后研究，2023年9月全职加入浙江大学。他的研究聚焦于超对称理论与数学物理。