Entanglement entropy, trace anomalies and holography

The holographic representation of the entanglement entropy of four-dimensional conformal field theories is studied. By generalizing the replica trick the anomalous terms in the entanglement entropy are evaluated. The same terms in the holographic representation are calculated by a method which does not require the solution of the equations of motion or a cut-off. The two calculations disagree for rather generic geometries. The reasons for the disagreement are analyzed.