Higher curvature Lagrangians, conformal symmetry and microscopic entropy of Killing horizons

TL;DR

This paper demonstrates that for a broad class of higher curvature Lagrangians, a Virasoro algebra with a central charge can be identified at Killing horizons, enabling entropy calculation via the Cardy formula.

Contribution

It introduces a method to derive Virasoro algebra structures and compute microscopic entropy for higher curvature gravity theories at Killing horizons.

Findings

Virasoro algebra with nontrivial central charge identified at Killing horizons

Entropy computed using Cardy formula matches expected results

Applicable to Lagrangians with arbitrary curvature dependence

Abstract

We impose a certain class of boundary conditions on Killing horizon and show for Lagrangians with arbitrary curvature dependence that one can identify a Virasoro algebra with nontrivial central charge and calculable Hamiltonian eigenvalue. Entropy can then be calculated from Cardy formula.