Holographic anomaly in 3d f(Ric) gravity

TL;DR

This paper applies holographic renormalization to 3D f(Ric) gravity, deriving boundary stress-tensor and analyzing anomalies, revealing how the central charge relates to BTZ black hole holography and Hawking radiation.

Contribution

It introduces a method to compute the boundary stress-tensor and anomalies in 3D f(Ric) gravity using holographic renormalization, extending previous Einstein gravity results.

Findings

Boundary stress-tensor derived for asymptotically AdS3 backgrounds.

Logarithmic divergence subtracted by a non-covariant term exchanging anomalies.

Central charge determined via BTZ holography and Hawking effect.

Abstract

By applying the holographic renormalization method to the metric formalism of f(Ric) gravity in three dimensions, we obtain the Brown-York boundary stress-tensor for backgrounds which asymptote to the locally AdS3 solution of Einstein gravity. The logarithmic divergence of the on-shell action can be subtracted by a non-covariant cut-off independent term which exchanges the trace anomaly for a gravitational anomaly. We show that the central charge can be determined by means of BTZ holography or in terms of the Hawking effect of a Schwarzschild black hole placed on the boundary.