Causal structure of a recent loop quantum gravity black hole collapse model

The causal structure of the recent loop quantum gravity black hole collapse model [1] is analysed. As spacetime only approximately diffeomorphism invariant up to powers $\hbar$, it not straight forwardly possible find global conformally compactified coordinates and construct Penrose diagram. Therefore, radial in- outgoing light rays are studied extract features sketch a It was found that eternal metric [2], which vacuum solution model, has horizon. However, in collapsing case travel through matter causally connect regions outside horizon -- present scenario. worked out this related shock wave discontinuity, allows travelling super-luminal along space-like trajectory from point view, but remaining time-like perspective. final diagram compact patch Reissner-Nordstr\"om Further, possibilities continuous with evolution studied. time-reversed also dynamical equations once continuously differentiable matching across minimal radius possible. This an everywhere process at cost infinite extended part infinitely bounce, whose extension constructed. Due analysis rays, diagrams these spacetimes.