Speaker: Prof. LIU Yi (Peking University)Venue: Room 210, Building 2, Haina Court, Zijingang CampusNote: Please scan the QR code in the picture above to register.

Speaker: Prof. WANG Guozhen (Fudan University)Venue: Room 210, Building 2, Haina Court, Zijingang CampusNote: Please scan the QR code in the picture above to register.

Venue: C100, Building 5, Haina Court, Zijingang Campus

Speaker: Prof. FANG Bohan (Peking University)Venue: Lecture Hall, East Building 7, Zijingang Campus

Speaker: Yuming Zhao (Institute for Quantum Computing and the Department of Pure Mathematics, University of Waterloo, Canada)Location: Dingding Group "2023-Autumn Quantum Theory Group"Abstract: A multivariate polynomial is said to be positive if it takes only non-negative values over reals. Hilbert's 17th problem concerns whether every positive polynomial can be expressed as a sum of squares of other polynomials. In general, we say a noncommutative polynomial is positive (resp. matrix positive) if plugging operators (resp. matrices) always yields a positive operator. Many problems in math and computer science are closely connected to deciding whether a given polynomial is positive and finding certificates (e.g., sum-of-squares) of positivity.In the study of nonlocal games in quantum information, we are interested in tensor product of free algebras. Such an algebra models a physical system with two spatially separated subsystems, where in each subsystem we can make different quantum measurements. The recent and remarkable MIP*=RE result shows that it is undecidable to determine whether a polynomial in a tensor product of free algebras is matrix positive. In this talk, I'll present joint work with Arthur Mehta and William Slofstra, in which we show that it is undecidable to determine positivity in tensor product of free algebras. As a consequence, there is no sum-of-square certificate for positivity in such algebras. I will also discuss relevant topics including self-testing of quantum systems and delegation of quantum computation.Profile of the speaker: Yuming Zhao is a Ph.D. candidate in the Institute for Quantum Computing and the Department of Pure Mathematics at the University of Waterloo, supervised by William Slofstra. Previously, he received his bachelor's degree in Mathematics and Applied Mathematics from Zhejiang University in 2019, under the supervision of Junde Wu. He is broadly interested in the mathematics of quantum information and computation. Recent areas of study include quantum self-testing, delegation of quantum computation, complexity theory in operator algebras, and approximate representation theory.Contact person: Junde Wu (wjd@zju.edu.cn)

Speaker: Prof. YANG WeiHost: Prof. LI LeiVenue: Zijingang Hall, Alumni Building, Zijingang CampusProfile of the speaker: Professor Wei Yang received her doctorate degree from Columbia University in 1991. Her postdoctoral training was at Yale University with Dr. Thomas A. Steitzat, Department of Biochemistry and Molecular Biophysics. She joined the NIH in 1995 as an independent Investigator and currently holds the Distinguished Investigator position in the Laboratory of Molecular Biology, NIDDK, NIH.Dr. Yang was elected a Member of National Academy of Sciences (NAS) in 2013 and Fellow of American Academy of Arts and Sciences (AAAS) in 2015. Among the many prestigious awards, she is the recipient of the Bea Singer Young Investigator Award (GRC, 2002), the Dorothy Crowfoot Hodgkin award (The Protein Society, 2011), and Mildred Cohn Award in Biological Chemistry (ASBMB, 2017). She also held adjunct Professorship at Johns Hopkins University.Her research interests include Mechanisms of DNA repair, replication and recombination, macromolecular assemblies, structure and enzyme catalysis, ATP in molecular motion, recognition and signaling.

Speaker: Prof. ZHONG Ping (University of Wyoming)Venue: Online (Tencent Meeting ID: 974-516-332)Abstract:In the 1980s, L. Brown introduced an analogue of eigenvalue distribution of a square matrix in the framework of operator algebras, now called Brown measure. The Brown measure is a fascinating object that has successful applications in operator algebras and non-Hermitian random matrix theory. The Brown measures of random variables in free probability theory can often predict the limiting eigenvalue distributions of non-Hermitian random matrices.I will speak on joint work with Hari Bercovici on the Brown measure of a sum of two free random variables, one of which is R-diagonal. This answers an open question of Biane and Lehner posed in early 2000s. It is shown that subordination functions that appear in the study of free additive convolution can detect some information about the Brown measure. In many cases, this leads to an explicit calculation of Brown measures. Some ideas were used implicitly in earlier works of Dykema, Haagerup and Schultz. In another joint work with Ching-Wei Ho, we prove that the Brown measure is the limiting eigenvalue distribution of a full rank perturbation of the single ring random matrix model under some mild assumptions.Contact person: Prof. LIU Weihua (lwh.math@zju.edu.cn)

Speaker: Dr. Chenyan Wu (The University of Melbourne）Venue: Lecture Hall, East Building 7, Zijingang CampusAbstract: Let $\pi$ be a cuspidal automorphic representation of a classical group or a metaplectic group. We show an exact relation between two invariants associated to $\pi$, one called the lowest occurrence index of $\pi$ which is an invariant arising from theta lifts and the other the location of the maximal positive pole of an Eisenstein series attached to $\pi$. As an application, we use this relation to show that certain global Arthur packets cannot contain cuspidal automorphic representations.

Speaker: Chak Fu Lam, Associate Editor of AMRHost: Prof. HU QiongjingVenue: Room 723, Building A, School of Management, Zijingang CampusAbstract: Join us for a conversation with Chak Fu Lam, who will provide an overview of what he believes is the primary cause of manuscript rejection at AMR. He will also offer insights on enhancing the prospects of receiving an R&R. Following a brief and interactive presentation, Chak Fu will address any inquiries and questions you may have pertaining to publishing in AMR.Profile of the speaker: Chak Fu Lam is an Associate Professor of Management at City University of Hong Kong. His research examines employee voice behavior, including why employees speak up and how managers respond to employee voice, and what makes employee voice sustainable over time. He has published research in Academy of Management Annals, Academy of Management Review, Journal of Applied Psychology, Journal of Management, and Personnel Psychology. In 2021, he was one of five reviewers to be awarded the title of Best Editorial Reviewer for his service to the Journal of Applied Psychology.Note: Please scan the QR code below to register.