Density matrices in quantum gravity

We study density matrices in quantum gravity, focusing on topology change. We argue that the inclusion of bra-ket wormholes in the gravity path integral is not a free choice, but is dictated by the specification of a global state in the multi-universe Hilbert space. Specifically, the Hartle-Hawki...

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Bibliographic Details
Main Author: Tarek Anous, Jorrit Kruthoff, Raghu Mahajan
Format: Article
Language:English
Published: SciPost 2020-10-01
Series:SciPost Physics
Online Access:https://scipost.org/SciPostPhys.9.4.045