Quantum-gravity effects outside the horizon spark black to white hole tunneling

By Hal M. Haggard, Carlo Rovelli. 2014

258 citations recorded by the source corpus.

We show that there is a classical metric satisfying the Einstein equations outside a finite spacetime region where matter collapses into a black hole and then emerges from a white hole. We compute this metric explicitly. We show how quantum theory determines the (long) time for the process to happen. A black hole can thus quantum-tunnel into a white hole. For this to happen, quantum gravity should affect the metric also in a small region outside the horizon: we show that contrary to what is commonly assumed, this is not forbidden by causality or by the semiclassical approximation, because quantum effects can pile up over a long time. This scenario alters radically the discussion on the black hole information puzzle.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/156b718234e78820ab72a310982bad3c0950b88a

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Citations in the corpus

A novel family of rotating black hole mimickers (2021, background): “The two estimates correspond to different ways of identifying the threshold: in the first, quantum gravity becomes dominant when the radius of the collapsing object becomes of order the Planck length, in the second when the density is of order the Planck density [46, 47].”
Transcending the ensemble: baby universes, spacetime wormholes, and the order and disorder of black hole information (2020, background): “The plethora of proposals for new physics that might be associated with obtaining this Page curve (including [3, 7–39]) were thus all properly viewed as speculative and contained at least some optimistic extrapolation or ad hoc ingredient.”
Quantum extension of the Kruskal spacetime (2018, unknown): “A symmetric behavior has been sought after and achieved using phenomenological inputs before [9]; it has been postulated in studies on black hole to white hole transition [43]; and arrived at by imposing physically motivated conditions on the black hole evaporation time scale [44].”
Phenomenological aspects of black holes beyond general relativity (2018, background): “• Timescale [29, 33]: the existence of a bounce of matter would be physically meaningful only if the timescale for the bounce (suitably defined in terms of the proper time of the relevant observers) is shorter than the (naive) evaporation time of the black hole,”