Hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion black holes

TL;DR

This paper investigates the hidden conformal symmetry of Einstein-Maxwell-Dilaton-Axion black holes, deriving their microscopic entropy and absorption cross sections, and establishing duality with conformal field theories for both extreme and non-extreme cases.

Contribution

It reveals the conformal symmetry in EMDA black holes and connects their thermodynamics to dual CFT descriptions, extending previous analyses to this specific class of black holes.

Findings

Conformal symmetry with specific temperatures in non-extreme EMDA black holes.

Microscopic entropy matches Bekenstein-Hawking law via Cardy formula.

Absorption cross section aligns with 2D CFT predictions.

Abstract

The hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion (EMDA) black holes is addressed in this paper. For the non-extreme one, employing the wave equation of massless scalars, the conformal symmetry with left temperature $T_{L}=\frac{M}{2\pi a}$ and right temperature $T_{R}=\frac{\sqrt{M^{2}-a^{2}}}{2\pi a}$ in the near region is found. The conformal symmetry is spontaneously broken due to the periodicity of the azimuthal angle. The microscopic entropy is derived by the Cardy formula and is fully in consistence with the Bekenstein-Hawking area-entropy law. The absorption cross section in the near region is calculated and exactly equals that in a 2D CFT. For the extreme case, by redefining the conformal coordinates, the duality between the solution space and CFT is studied. The microscopic entropy is found to exactly agree with the area-entropy law.