Description
This is the first of a two-part talk on non-invertible symmetries in Maxwell theory in four dimensions. The second one will be given by Pierluigi Niro. I will argue that Maxwell theory has three infinite sets of non-invertible defects. The first set can be obtained by higher-gauging a discrete subgroup of the electric one-form symmetry along a codimension-1 defect. Similarly, we can higher-gauge a discrete subgroup of the magnetic one-form symmetry and construct a second infinite set of topological defects. Then, I will argue that we can combine elements of the SL(2,Z) duality group with the gauging of one-form symmetries in half-space to define a third infinite set of non-invertible symmetries.
