Probing Loop Quantum Gravity with Evaporating Black Holes

This Letter aims at showing that the observation of evaporating black holes should allow the usual Hawking behavior to be distinguished from loop quantum gravity (LQG) expectations. We present a full Monte Carlo simulation of the evaporation in LQG and statistical tests that discriminate between competing models. We conclude that contrarily to what was commonly thought, the discreteness of the area in LQG leads to characteristic features that qualify evaporating black holes as objects that could reveal quantum gravity footprints.

Figure 1

Spectrum of emitted particles in LQG, in the pure Hawking case, and in the Mukhanov-Bekenstein approach, from top to bottom.

Figure 2

Number of evaporating black holes that have to be observed as a function of the relative error on the energy reconstruction of the emitted leptons for different confidence levels (the gray scale corresponds to the number of standard deviations). The first row corresponds to the discrimination between LQG and the Hawking hypothesis and the second row between LQG and the Mukhanov-Bekenstein hypothesis.

Figure 3

Instantaneous spectrum of a $\sim 100\mathrm{keV}$ black hole taking into account the LQG modulation of the entropy.