张欣宇研究员，浙江大学，于2025年5月15日16:00在物质科研楼C座11层1124做题为“Physical approach to K-theoretic Donaldson invariants”的报告，欢迎感兴趣者参加。

Topic: Physical approach to K-theoretic Donaldson invariants

Speaker: Prof.Xinyu Zhang

Coordinates: PCFT C1124, 16:00, Thursday, May 15

Abstract: A cornerstone of modern mathematical physics is the profound interplay between geometric structures and gauge theory. After briefly reviewing some aspects of Donaldson-Witten theory, we will sketch a systematic physical approach to its K-theoretic lift using the path integral of 5d N=1 SU(2) super Yang-Mills theory on $X \times S^1$, where $X$ is a closed, smooth four-manifold. After a partial topological twist along $X$, the correlation functions of the theory generate K-theoretic Donaldson invariants. For a large class of four-manifolds $X$, we successfully evaluate these invariants by reducing the 5d path integral to a low-energy effective theory on $X$.