Symmetries, Horizons, and Black Hole Entropy

TL;DR

This paper explores how conformal symmetry near black hole horizons may explain their universal thermodynamic properties and entropy, proposing a Goldstone-boson-like mechanism as a key feature.

Contribution

It introduces a symmetry-based framework linking conformal invariance and black hole entropy, highlighting a universal explanation across quantum gravity approaches.

Findings

Conformal symmetry near horizons underpins black hole thermodynamics.

Goldstone-boson-like excitations emerge from symmetry breaking.

Universal entropy results are explained by this symmetry perspective.

Abstract

Black holes behave as thermodynamic systems, and a central task of any quantum theory of gravity is to explain these thermal properties. A statistical mechanical description of black hole entropy once seemed remote, but today we suffer an embarrassment of riches: despite counting very different states, many inequivalent approaches to quantum gravity obtain identical results. Such ``universality'' may reflect an underlying two-dimensional conformal symmetry near the horizon, which can be powerful enough to control the thermal characteristics independent of other details of the theory. This picture suggests an elegant description of the relevant degrees of freedom as Goldstone-boson-like excitations arising from symmetry breaking by the conformal anomaly.