On the logarithmic coefficient of the entanglement entropy of a Maxwell field

Understand

We elucidate the mismatch between the $A$-anomaly coefficient and the coefficient of the logarithmic term in the entanglement entropy of a Maxwell field.

• In contrast to the usual assumptions about the protection of renormalization group charges at the infrared, the logarithmic term is different for a free Maxwell field and a Maxwell field interacting with heavy charges.
• This is possible because of the presence of superselection sectors in the IR theory.
• However, the correction due to the coupling with charged vacuum fluctuations, that restores the anomaly coefficient, is independent of the precise UV dynamics.