Title Adults: Actions of Homeomorphism Groups on Manifolds
Abstract I will talk about my joint work with Kathryn Mann on actions of homeomorphism groups on manifolds. We prove an orbit classification problem which says that any action in some sense is similar to the diagonal action on products.
About the speaker Professor Lei CHEN is an Associate Professor at the Morningside Center of Mathematics, Chinese Academy of Sciences. She obtained her Bachelor’s degree from Peking University and her PhD from the University of Chicago. Prof. CHEN held a postdoctoral position at Caltech and was previously an Assistant Professor at the University of Maryland.
Professor Lynn HELLER, Beijing Institute of Mathematical Sciences and Applications
Title On the Enclosed Value of Constant Mean Curvature Surfaces in 3-Space
Abstract We derive a general formula for the enclosed volume of CMC surfaces in R^3 with translational periods in a lattice in terms of area and the Wess-Zumino-Witten term generalising the well-known Minkowski formula for compact CMC surfaces. We then show how apply the formula to obtain values for the enclosed volume in various examples by expressing it as a gauge invariant quantity. This allows us to give a numerical counter example for the periodic isoperimetric problem, where the minimisers were conjectured to be spheres, cylinders or two planes.
About the speaker Professor Lynn HELLER was born in Wuhan and moved with her mother at the age of 8 to Göttingen, Gemany. She studied economics at the FU Berlin and Mathematics at TU Berlin from 2003-2007 and obtained her PhD in mathematics at Eberhard Karls University Tübingen in 2012. Before joining BIMSA she was juniorprofessor at Leibniz University in Hannover. For the period 2025-2028 Lynn HELLER is serving as a member of the Committee on Publishing (CoP) of the International Mathematical Union (IMU).
Professor Ling Yan HUNG, Tsinghua University
Title Seeking Continuum from a Lattice: Categorical Symmetries vs Non-Perturbative Physics
Abstract Strongly interacting field theory (such as the standard model in low energy) has confounded physicists for more than half a century. Recently people realise that there is a radical generalisation of the concept of symmetries — and these structures are mathematically described by tensor categories. These new structures appear to help us to look for UV complete critical lattice models that provides a non-perturbative description of continuous field theories by taking thermodynamic limit. This could be a new route towards understanding and making accurate computations in non- perturbative theories.
About the speaker Professor Ling Yan HUNG completed her undergraduate studies at the University of Oxford and pursued her master's and doctoral degrees at the University of Cambridge. She conducted postdoctoral research at the Perimeter Institute for Theoretical Physics in Canada and in the Department of Physics at Harvard University. After returning to China, she was appointed as a tenured professor in the Department of Physics at Fudan University. In the fall of 2022, she joined the Yau Mathematical Sciences Center. Her primary research focuses on the gauge/gravity duality (AdS/CFT Correspondence) and its connections to quantum entanglement and topological field theories. She has published over 80 research papers and received the "Qiu Shi Outstanding Young Scholar Award" in 2015.
Professor Jianghua LU, The University of Hong Kong
Title What is Poisson Geometry?
Abstract In this talk , we give a brief introduction to Poisson geometry and its connections to Lie theory and cluster algebras.
About the speaker Professor Jianghua LU received her bachelor's degree from Beijing University and her PhD from the University of California, Berkeley. She has held teaching and visiting positions at MIT, the IAS at Princeton, and the University of Arizona, and she is currently a professor of mathematics at the University of Hong Kong. Her research interests include Poisson geometry, symplectic geometry, Lie theory and cluster algebras.
