Quantum Computation vs. Firewalls
Abstract
In this paper we discuss quantum computational restrictions on the types of thought experiments recently used by Almheiri, Marolf, Polchinski, and Sully to argue against the smoothness of black hole horizons. We argue that the quantum computations required to do these experiments take a time which is exponential in the entropy of the black hole under study, and we show that for a wide variety of black holes this prevents the experiments from being done. We interpret our results as motivating a broader type of non-locality than is usually considered in the context of black hole thought experiments, and claim that once this type of non-locality is allowed there may be no need for firewalls. Our results do not threaten the unitarity of of black hole evaporation or the ability of advanced civilizations to test it.
Cite
@article{arxiv.1301.4504,
title = {Quantum Computation vs. Firewalls},
author = {Daniel Harlow and Patrick Hayden},
journal= {arXiv preprint arXiv:1301.4504},
year = {2015}
}
Comments
Significant revision of sections 4.1-4.3; the general discussion of error correction is corrected (heh), and its relation to the AMPS experiment is made more explicit. Also a new section 3.4 is added, which gives a rigorous proof of the hardness of decoding for generic initial states. Comments are added to the introduction about an external entity "pausing" the black hole