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arXiv · 2111.07107

A comment on a fine-grained description of evaporating black holes with baby universes

Norihiro Iizuka·Akihiro Miyata·Tomonori Ugajin
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Abstract

We study a partially fine-grained description of an evaporating black hole by introducing an open baby universe with a boundary. Since the Page's calculation of the entropy of Hawking radiation involves an ensemble average over a class of states, one can formally obtain a fine-grained state by purifying this setup. For AdS black holes with a holographic dual, this purification amounts to introducing an additional boundary (i.e., baby universe) and then connecting it to the original black hole through an Einstein-Rosen bridge. We uncover several details of this setup. As applications, we briefly discuss how this baby universe modifies the semi-classical gravitational Gauss law as well as the gravitational dressing of operators behind the horizon.

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Norihiro Iizuka, Akihiro Miyata, Tomonori Ugajin. 2021-11-13. A comment on a fine-grained description of evaporating black holes with baby universes. https://doi.org/10.1007/jhep09(2022)158

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