The holographic Weyl anomaly

We calculate the Weyl anomaly for conformal field theories that can be described via the adS/CFT correspondence. This entails regularizing the gravitational part of the corresponding supergravity action in a manner consistent with general covariance. Up to a constant, the anomaly only depends on the dimension d of the manifold on which the conformal field theory is defined. We present concrete expressions for the anomaly in the physically relevant casesd = 2,4 and 6. In d = 2 we find for the central charge c = 3l/2G_N, in agreement with considerations based on the asymptotic symmetry algebra of adS₃. In d = 4 the anomaly agrees precisely with that of the corresponding = 4 superconformal SU(N) gauge theory. The result in d = 6 provides new information for the (0, 2) theory, since its Weyl anomaly has not been computed previously. The anomaly in this case grows as N³, where N is the number of coincident M5 branes, and it vanishes for a Ricci-flat background.