2016/05/31 by Marios Christodoulou, Carlo Rovelli, Simone Speziale +1 · 2 citations
Physics and Astronomy · #gr-qc #astro-ph.CO #astro-ph.HE #hep-th
paper · pdf · doi:10.1103/physrevd.94.084035
published as Phys. Rev. D 94, 084035 (2016) · We consider this paper important. 17 pages, 13 figures
arxiv created 2016/09/14 · arxiv updated 2016/10/26
A gravitationally collapsed object can bounce-out from its horizon via a tunnelling process that violates the classical equations in a finite region. Since tunnelling is a non-perturbative phenomenon, it cannot be described in terms of quantum fluctuations around a classical solution and a background-free formulation of quantum gravity is needed to analyze it. Here we use Loop Quantum Gravity to compute the amplitude for this process, in a first approximation. The amplitude determines the tunnelling time as a function of the mass. This is the key information to evaluate the astrophysical relevance of this process. The calculation offers a template and a concrete example of how a background-free quantum theory of gravity can be used to compute a realistical observable quantity.