Speaker: Pro.ChenChang Zhu(University of Göttingen)

Title: Higher groups in higher gauge theory

Time & Location: Thu,   Jan.3, 2019 , AM:11:00-12:00, Room 4318, Building No.4, Wushan Campus

  Abstract                

There has been much recent development on higher symmetries in topological orders as the study of topological phase of maters has become a very active field in condensed matter physics. In this talk, we will carry out the mathematical foundation of a recent joint project with Tian Lan and Xiao-Gang Wen in the above direction. Higher groups are group objects in a higher category. In a very concise way, they can be realised as a simplicial object satisfying suitable Kan conditions. We will give a more explicit algebraic model to realise some of them. This model is between the target of Dold-Kan functor and the skeleton case. These higher groups are then used in the sigma model as the target space to realise various physical meaningful phases.