Conformal nature of the Hawking radiation

TL;DR

This paper demonstrates that Hawking radiation's thermal spectrum naturally emerges from the conformal symmetry of the event horizon, without assuming thermal equilibrium, linking black hole thermodynamics to underlying algebraic structures.

Contribution

It shows that Hawking thermodynamics arises from the Virasoro algebraic structure of microscopic black holes modeled by conformal field theory, avoiding thermal equilibrium assumptions.

Findings

Hawking radiation spectrum is derived from conformal symmetry.

Black hole thermodynamics is a consequence of Virasoro algebra.

Unitary evolution of microscopic black holes explains thermal features.

Abstract

String theory usually represents quantum black holes as systems whose statistical mechanics reproduces Hawking's thermodynamics in a very satisfactory way. Complicated brane theoretical models are worked out, as quantum versions of Supergravity solutions. These models are then assumed to be in thermal equilibrium: this is a little cheating, because one is looking for an explanation of the seeming thermodynamical nature of black holes, so they cannot be {\it assumed} to be finite temperature systems! In the model presented here, the black body spectrum arises with no statistical hypothesis as an approximation of the unitary evolution of microscopic black holes, which are always described by a 1+1 conformal field theory, characterized by some Virasoro algebra. At the end, one can state that {\it the Hawking-thermodynamics of the system is a by-product of the algebraic Virasoro-symmetric nature of the event horizon}. This is {\it the central result} of the present work.