Aspects of Flat/CCFT Correspondence

TL;DR

This paper explores the Flat/CCFT correspondence, showing how a Cardy-like formula in CCFT_2 arises from contraction of a CFT_2 formula, linking flat-space gravity and boundary field theories.

Contribution

It demonstrates that the CCFT_2 Cardy-like formula can be derived from the contraction of the CFT_2 formula related to BTZ black hole entropy.

Findings

The CCFT_2 Cardy-like formula is obtained via contraction of the CFT_2 formula.

The modified Cardy formula describes the entropy of BTZ black hole inner horizons.

The approach provides a bridge between AdS/CFT and flat-space holography.

Abstract

Flat/CCFT is a correspondence between gravity in asymptotically flat backgrounds and a field theory which is given by contraction of conformal field theory. In order to find a dictionary for Flat/CCFT correspondence one can start from the AdS/CFT and take the contraction of CFT in the boundary as the dual description of the flat-space limit (zero cosmological constant limit) of the asymptotically AdS spacetimes in the bulk side. In this paper we show that the Cardy-like formula of CCFT_2 is given by contraction of a proper formula in the CFT_2. This formula is the modified Cardy formula which gives the entropy of inner horizon of BTZ black holes.