title: Entanglement entropy flow and the Ward identity.
abstract: We derive differential equations for the flow of entanglement entropy as a function of the metric and the couplings of the theory. The variation of the universal part of entanglement entropy under a local Weyl transformation is related to the variation under a local change in the couplings. We show that this relation is, in fact, equivalent to the trace Ward identity. As a concrete application of our formalism, we express the entanglement entropy for massive free fields as a two-point function of the energy-momentum tensor.
authors.affiliation: Center for Theoretical Physics and Department of Physics, University of California, Berkeley, California 94720, USA and Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rosenhaus
authors.affiliation: Center for Theoretical Physics and Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Smolkin