The Fefferman-Graham Ambiguity and AdS Black Holes

TL;DR

This paper explores the role of boundary degrees of freedom in asymptotically AdS space-times, linking them to black hole solutions and boundary conformal field theories, with explicit analysis in 2+1 dimensions.

Contribution

It demonstrates how Fefferman-Graham boundary fields encode black hole parameters and relate to boundary energy-momentum tensors, especially illustrating the 2+1 dimensional case.

Findings

Boundary degrees of freedom generate all AdS black holes.

In 2+1 dimensions, these fields relate to the Virasoro algebra and BTZ black hole parameters.

The boundary fields correspond to the Liouville field in curved backgrounds.

Abstract

Asymptotically anti-de Sitter space-times in pure gravity with negative cosmological constant are described, in all space-time dimensions greater than two, by classical degrees of freedom on the conformal boundary at space-like infinity. Their effective boundary action has a conformal anomaly for even dimensions and is conformally invariant for odd ones. These degrees of freedom are encoded in traceless tensor fields in the Fefferman-Graham asymptotic metric for any choice of conformally flat boundary and generate all Schwarzschild and Kerr black holes in anti-de Sitter space-time. We argue that these fields describe components of an energy-momentum tensor of a boundary theory and show explicitly how this is realized in 2+1 dimensions. There, the Fefferman-Graham fields reduce to the generators of the Virasoro algebra and give the mass and the angular momentum of the BTZ black holes. Their local expression is the Liouville field in a general curved background.