How red is a quantum black hole?

TL;DR

This paper explores how quantum gravity constraints, specifically a bound on curvature, influence black hole radiation, leading to limits on redshift, temperature, and the prediction of a Planck-scale remnant.

Contribution

It introduces a quantum curvature bound that constrains black hole evaporation and predicts a remnant, addressing key puzzles in black hole physics.

Findings

Maximum black hole temperature derived

Upper limit on Hawking particle redshift established

Prediction of a Planck-scale black hole remnant

Abstract

Radiating black holes pose a number of puzzles for semiclassical and quantum gravity. These include the transplanckian problem -- the nearly infinite energies of Hawking particles created near the horizon, and the final state of evaporation. A definitive resolution of these questions likely requires robust inputs from quantum gravity. We argue that one such input is a quantum bound on curvature. We show how this leads to an upper limit on the redshift of a Hawking emitted particle, to a maximum temperature for a black hole, and to the prediction of a Planck scale remnant.