Description
At least intuitively, edge modes in gauge theory are the finite-boundary analogues of the soft and Goldstone modes familiar from asymptotic symmetries. However, most treatments of edge modes are either limited to kinematics or view them as superselection labels. I show how to treat edge modes as dynamical degrees of freedom. I find that their contribution to the partition function resolves certain discrepancies in the literature, and allows the entanglement entropy to be written as a genuine trace over a density matrix.
