Black holes in effective loop quantum gravity: Hawking radiation

TL;DR

This paper investigates black hole evaporation within an effective loop quantum gravity framework, demonstrating consistent Hawking radiation results, the impact of holonomy corrections on evaporation rates, and the role of covariant semi-classical stress-energy tensors.

Contribution

It introduces a covariant approach to loop quantum gravity black holes, showing consistent Hawking radiation results and analyzing holonomy effects on evaporation.

Findings

Hawking radiation results are consistent across multiple studies due to covariance.

Holonomy corrections slow down black hole evaporation.

A new net stress-energy tensor concept enables direct evaporation rate calculations.

Abstract

Emergent modified gravity provides a covariant framework for holonomy effects in models of loop quantum gravity with consistent black hole solutions coupled to a scalar field. Several independent studies of the Hawking thermal distribution are shown here to lead to the same final result. This internal consistency is a direct consequence of general covariance, which is analogous to the situation in classical general relativity but highly nontrivial in the context of modified canonical gravity. Holonomy corrections to the evaporation rate enter through the greybody factor, slowing down the evaporation process when the holonomy modification function decreases monotonically. Accounting for backreaction, corrected covariant semi-classical stress-energy tensors are computed in various vacuum states. Thanks to these results, the new concept of a net stress-energy tensor makes it possible to compute evaporation rates directly from energy conservation laws.