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arXiv · 2201.11132

Singularities From Entropy

Raphael Bousso·Arvin Shahbazi-Moghaddam
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Abstract

Assuming the Bousso bound, we prove a singularity theorem: if the light rays entering a hyperentropic region contract, then at least one light ray must be incomplete. "Hyperentropic" means that the entropy of the region exceeds the Bekenstein-Hawking entropy of its spatial boundary. Our theorem provides a direct link between singularities and quantum information. The hyperentropic condition replaces the noncompactness assumption in Penrose's theorem, so our theorem is applicable even in a closed universe. In an asymptotically de Sitter spacetime, for example, a big bang singularity can be diagnosed from the presence of dilute radiation at arbitrarily late times. In asymptotically flat space, Penrose's theorem can be recovered by adding soft radiation.

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Raphael Bousso, Arvin Shahbazi-Moghaddam. 2022-01-26. Singularities From Entropy. https://doi.org/10.1103/physrevlett.128.231301

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