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arXiv · 2104.03253

Violation of Unitarity in Gravitational Subregions

Aron C. Wall
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Abstract

This essay contends that in quantum gravity, some spatial regions do not admit a unitary Hilbert space. Because the gravitational path integral spontaneously breaks CPT symmetry, "states" with negative probability can be identified on either side of trapped surfaces. I argue that these negative norm states are tolerable, by analogy to quantum mechanics. This viewpoint suggests a resolution of the firewall paradox, similar to black hole complementarity. Implications for cosmology are briefly discussed.

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Aron C. Wall. 2021-04-07. Violation of Unitarity in Gravitational Subregions. https://doi.org/10.1142/s0218271821420141

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