Noether current from the surface term of gravitational action, Virasoro algebra and horizon entropy

TL;DR

This paper presents a straightforward method to derive horizon entropy using the Virasoro algebra and Noether currents from the surface term of gravitational action, avoiding ambiguities and offering deeper physical insight.

Contribution

It introduces a simple, ambiguity-free approach to compute horizon entropy via the Virasoro algebra from the surface term of gravitational action.

Findings

Virasoro algebra with central extension derived from Noether currents

Horizon entropy obtained directly from algebraic structure

Method clarifies physical motivation behind entropy calculation

Abstract

We describe a simple way of obtaining horizon entropy using the approach based on the Virasoro algebra and central charge. We show that the Virasoro algebra defined by the Noether currents corresponding to the surface term of gravitational action, for the diffeomorphisms which leave the horizon structure unaltered, has a central extension that directly leads to the horizon entropy. In this approach there are no ambiguities in the calculation of the central charge. We explain why this approach is physically well motivated and could provide greater insight into the nature of horizon entropy.