Entanglement entropy of gauge fields is calculated using the partition function in curved spacetime with a boundary. Deriving a Gibbons-Hawking-like term from a Becchi-Rouet-Stora-Tyutin (BRST) action produces a Wald-entropy-like codimension-2 surface term. It is further suggested that boundary degrees of freedom localized on the entanglement surface generated from the gauge redundancy could be used to resolve a subtle mismatch in a universal conformal anomaly-entanglement entropy relation.

• Received 15 December 2014

DOI:https://doi.org/10.1103/PhysRevD.92.025010