Boundary symmetries of (2+1)D topological orders
arXiv:2408.10832
Abstract
We elaborate an algebraic framework for describing internal topological symmetries of gapped boundaries of (2+1)D topological orders. We present a categorical obstruction to the coherence of bulk group symmetry and boundary symmetries in terms of liftings of categorical actions on the bulk theory to a certain 2-group of boundary symmetries.
18 pages, 11 figures. Comments welcome