Title： Witt groups and signatures of modular tensor categories

Abstract： In this talk, we introduce the notion of signatures of fusion categories. These signatures can be extended to Witt invariants of modular or super-modular categories. The higher central charges of any modular category can be expressed in terms of its first central charge and signature. The signatures of an infinite sequence of quantum group modular categories are proved to be linearly independent, which implies a conjecture of Davydov-Nikshych-Ostrik on the super-Wittgroup. This talk is based on a joint work with Eric Rowell, Yilong Wang and Qing Zhang.

Speaker：Siu-Hung Ng，Louisiana State University

Professor Siu-Hung Ng’s present research interests lie in the area of Hopf algebra, quasi-Hopf algebra and tensor category. His main focus is aimed at the classification of finite dimensional Hopf algebras in particular dimensions, and the study of invariants of pivotal tensor categories such as Frobenius-Schur indicators and exponents. He has published more than 30 papers in important international journals, such as, J. Amer. Math. Soc, Adv. Math, Tran. Amer. Math. Soc, Comm. Math. Phys, Int Math. Res. Not, etc.

Date：10:30am-11:30am 2021-6-19（Saturday）.

Venue: 204

Tencent Meeting ID：291 660 583  

Organizer：School of Mathematical Science

Students and teachers who are interested in Hopf algebras and tensor categoriesare welcome.