Lecture Content：

We introduce the von Neumann's inequality for contractions and give several proofs of it. Some proofs are operator theoretic, some are function theoretic.

Speaker Introduction:

Wang Yi, a professor at Chongqing University, is recognized as a "Hongshen Outstanding Scholar" and a national-level high-profile young talent. He graduated from Fudan University and Texas A&M University in the USA. His research primarily focuses on the study of operators on analytic Hilbert modules. He has made significant contributions to the Arveson-Douglas conjecture and related geometric invariants, as well as research on Toeplitz operators. His related papers have been published in renowned mathematical journals such as Advances in Mathematics, Proceedings of the London Mathematical Society, Journal of Functional Analysis, and Indiana University Mathematics Journal.