Witt groups and the signature
报告专家：王亦龙 助理研究员（北京雁栖湖应用数学研究院）
报告时间：2月25日（星期二）下午16:00-17:00
报告地点：国家天元数学西南中心516报告厅
报告摘要：Braided fusion categories are categorical generalizations of quadratic forms on finite abelian groups that appears naturally in many aspects of mathematics and physics such as rational conformal field theory and topological quantum field theory. While we are still far away from a complete classification of braided fusion categories, certain group structures that generalize the classical Witt group of quadratic forms emerge to help us at least understand some relations among these categories. In this talk, we will give a brief introduction to the categorical Witt groups. Then we will define a numerical invariant of the Witt groups called the signature that generalizes the Jacobi symbol, and demonstrate how the signature helps us determine the structure of certain subgroups of the Witt groups. This is based on the joint work with Siu-Hung Ng, Eric Rowell and Qing Zhang.
专家简介：王亦龙，北京雁栖湖应用数学研究院助理研究员，于2018年从俄亥俄州立大学数学专业博士毕业，之后在路易斯安那州立大学任博士后，并于2021年加入北京雁栖湖应用数学研究院。主要研究方向为量子代数与量子拓扑，具体课题包括模张量范畴及其对应的拓扑量子场论的代数与数论性质，主持国家自然科学基金青年项目一项，在Comm. Math. Phys.，Adv. Math等杂志发表论文10余篇。
邀请人：任丽
