Black hole horizons from within loop quantum gravity

TL;DR

This paper proposes a new approach in loop quantum gravity where black hole horizon degrees of freedom are derived directly from the bulk quantum states, simplifying the quantization process.

Contribution

It introduces a framework where horizon degrees of freedom are not quantized separately but are components of the bulk quantum states, aligning with classical horizon properties.

Findings

Horizon theory resembles previous results for spherical topology

No separate quantization of horizon degrees of freedom needed

Framework simplifies understanding of quantum horizons

Abstract

In general relativity, the fields on a black hole horizon are obtained from those in the bulk by pullback and restriction. Similarly, in quantum gravity, the quantized horizon degrees of freedom should result from restricting, or pulling-back, the quantized bulk degrees of freedom. This is not yet fully realized in the - otherwise very successful - quantization of isolated horizons in loop quantum gravity. In this work we outline a setting in which the quantum horizon degrees of freedom are simply components of the quantized bulk degrees of freedom. There is no need to quantize them separately. We present evidence that for a horizon of sphere topology, the resulting horizon theory is remarkably similar to what has been found before.