Hawking radiation from a spherical loop quantum gravity black hole

Abstract

We introduce quantum field theory on quantum space-times techniques to characterize the quantum vacua as a first step towards studying black hole evaporation in spherical symmetry in loop quantum gravity and compute the Hawking radiation. We use as quantum space time the recently introduced exact solution of the quantum Einstein equations in vacuum with spherical symmetry and consider a spherically symmetric test scalar field propagating on it. The use of loop quantum gravity techniques in the background space-time naturally regularizes the matter content, solving one of the main obstacles to back reaction calculations in more traditional treatments. The discreteness of area leads to modifications of the quantum vacua, eliminating the trans-Planckian modes close to the horizon, which in turn eliminates all singularities from physical quantities, like the expectation value of the stress energy tensor. Apart from this, the Boulware, Hartle--Hawking and Unruh vacua differ little from the treatment on a classical space-time. The asymptotic modes near scri are reproduced very well. We show that the Hawking radiation can be computed, leading to an expression similar to the conventional one but with a high frequency cutoff. Since many of the conclusions concern asymptotic behavior, where the spherical mode of the field behaves in a similar way as higher multipole modes do, the results can be readily generalized to non spherically symmetric fields.

15 pages, no figures, several points clarified

References in corpus (3)

• Quantum field theory on a cosmological, quantum space-time
• Algebraic Quantum Gravity (AQG) II. Semiclassical Analysis
• Short-distance contribution to the spectrum of Hawking radiation

Cited by in corpus (24)

• Quantum Extension of the Kruskal Space-time
• Covariance in models of loop quantum gravity: Spherical symmetry
• Properties of a recent quantum extension of the Kruskal geometry
• Covariance in models of loop quantum gravity: Gowdy systems
• Gravitational lensing by a black hole in effective loop quantum gravity
• Emergent modified gravity: Covariance regained
• Spherically symmetric sector of self dual Ashtekar gravity coupled to matter: Anomaly-free algebra of constraints with holonomy corrections
• The Thiemann Complexifier and the CVH algebra for Classical and Quantum FLRW Cosmology
• Loop quantum black hole
• Quantum space-time of a charged black hole
• Anomaly-free deformations of spherical general relativity coupled to matter
• Brief review on black hole loop quantization
• Emergence of string-like physics from Lorentz invariance in loop quantum gravity
• Holonomy and inverse-triad corrections in spherical models coupled to matter
• Finite-distance gravitational deflection of massive particles by a rotating black hole in loop quantum gravity
• Understanding quantum black holes from quantum reduced loop gravity
• Exploring alternatives to the Hamiltonian calculation of the Ashtekar-Olmedo-Singh black hole solution
• Extended phase space quantization of a black hole interior model in Loop Quantum Cosmology
• Symmetry Reduced Loop Quantum Gravity: A Bird's Eye View
• Emergent modified gravity coupled to scalar matter
• Rainbow metric from quantum gravity: anisotropic cosmology
• Schrödinger-like quantum dynamics in loop quantized black holes
• Lessons for loop quantum gravity from emergent modified gravity
• Kiselev black strings: the charged rotating solutions