Speaker: Maissam Barkeshli (Maryland)
Title: Defects and higher symmetries in (3+1)D topological phases of matter
Abstract: (3+1)D topological phases of matter can host interesting classes of non-trivial topological defects of varying codimension, of which the well-known point charges and flux loops are special cases. The complete algebraic structure of these defects defines a higher category, and can be viewed as an emergent higher symmetry. This plays an important role both in the classification of phases of matter and the possible fault-tolerant logical operations in quantum error correcting codes. In this talk I will discuss some recent progress in our understanding of the properties of invertible defects and higher group symmetries in (3+1)D topological phases of matter. Along the way I will review some progress over the past few years in characterizing topological phases of matter and their defects in low dimensions.