Microscopic Entropy of Non-dilatonic Branes: a 2D approach

TL;DR

This paper demonstrates that the microscopic entropy of non-dilatonic branes can be accurately described using a two-dimensional AdS/CFT approach, matching the Bekenstein-Hawking entropy through a scalar field-induced conformal symmetry breaking.

Contribution

It introduces a 2D gravity model from dimensional reduction that captures the entropy of non-dilatonic branes via an AdS_2/CFT_1 duality with a scalar field.

Findings

Exact agreement between CFT_1 entropy and Bekenstein-Hawking entropy.

The scalar field breaks conformal symmetry and generates a central charge.

The model provides a finite-temperature effective description of branes.

Abstract

We investigate non-dilatonic 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 AdS_p+2/CFT_p+1 correspondence at finite temperature admits an effective description in terms of a AdS_2/CFT_1 duality endowed with a scalar field, which breaks the conformal symmetry and generates a non-vanishing central charge. The entropy of the CFT_1 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 CFT_1 entropy and the Bekenstein-Hawking entropy of the brane.