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Hawking Evaporation and the Fate of Black Holes in Loop Quantum Gravity

Idrus Husin Belfaqih1,*, Martin Bojowald2,†, Suddhasattwa Brahma1,3,‡, and Erick I. Duque2,§

  • *Contact author: i.h.belfaqih@sms.ed.ac.uk
  • †Contact author: bojowald@psu.edu
  • ‡Contact author: suddhasattwa.brahma@gmail.com
  • §Contact author: eqd5272@psu.edu
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Phys. Rev. Lett. 135, 161501 – Published 16 October, 2025

DOI: https://doi.org/10.1103/t6q4-4l77

Abstract

A recent covariant formulation, that includes nonperturbative effects from loop quantum gravity (LQG) as self-consistent effective models, has revealed the possibility of nonsingular black hole solutions. The new framework makes it possible to couple scalar matter to such LQG black holes and derive Hawking radiation in the presence of quantum spacetime effects while respecting general covariance. Standard methods to derive particle production both within the geometric optics approximation and the Parikh–Wilczek tunnelling approach are therefore available and confirm the thermal nature of Hawking radiation. The covariant description of scale-dependent decreasing holonomy corrections maintains Hawking temperature as well as universality of the low-energy transmission coefficients, stating that the absorption rates are proportional to the horizon area at leading order. Quantum-geometry effects enter the thermal distribution only through subleading corrections in the graybody factors. Nevertheless, they do impact energy emission of the black hole and its final state in a crucial way regarding one of the main questions of black-hole evaporation: whether a black-to-white-hole transition, or a stable remnant, is preferred. For the first time, a first-principles derivation, based on a discussion of backreaction, finds evidence that points to the former outcome.

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Phys. Rev. Lett. 135, 161501– Published 16 October, 2025
  • Received 17 April 2025
  • Revised 17 June 2025
  • Accepted 18 September 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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