MICROSCOPIC ENTROPY OF NON-DILATONIC BRANES: A 2-D APPROACH

We investigate nondilatonic p-branes in the near-extremal, near-horizon regime. A two-dimensional gravity model, obtained from dimensional reduction, gives an effective description of the brane. We show that the AdS2/CFT1 correspondence at finite temperature admits an effective description in terms of a AdS2/CFT1 duality endowed with a scalar field, which breaks the conformal symmetry and generates a nonvanishing central charge. The entropy of the CFT1 is computed using Cardy formula. Fixing in a natural way a free, dimensionless, parameter introduced in the model by a renormalization procedure, we find exact agreement between the CFT1 entropy and the Bekenstein-Hawking entropy of the brane