Aspects of Flat/CCFT Correspondence

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.