Abstract

Non-perturbative quantum gravity prevents the formation of curvature singularities, and replaces it with a quantum region evocatively called a “Planck Star”. The presence of quantum fluctuations of the metric may induce black holes to decay into a white hole. These quantum fluctuations appears in a characteristic time shorter than the evaporation time, therefore the black-to-white transition can solve the puzzle of the ultimate fate of black holes, and provides a solution for the information paradox. Calculating the exact black-hole lifetime is a major challenge for a quantum gravity theory, currently under investigation in Loop Quantum Gravity. The phenomenon opens a new window in quantum-gravity phenomenology, in connection with the existence of primordial black holes. Primordial black holes decaying in this way appears compatible with the current cosmological constraints. I discuss the possibility to observe an astrophysical emission from the explosion of primordial black hole in different wavelengths, including the mysterious Fast Radio Bursts. Those emissions can be discriminated from other astrophysical sources because of the peculiar way the emitted wavelength scales with the distance. In particular, the spectrum of the diffuse radiation produced by those objects presents a distortion due to this scaling.