Emergent unitarity in de Sitter from matrix integrals

Journal Article · 13 December 2021 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/jhep12(2021)089 · OSTI ID:1976592

Cotler, Jordan ^[1]; Jensen, Kristan ^[2]

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1. Stanford University, CA (United States). Stanford Inst. of Theoretical Physics (ITP); San Francisco State Univ., CA (United States)
2. San Francisco State University, CA (United States)

We study Jackiw-Teitelboim gravity with positive cosmological constant as a model for de Sitter quantum gravity. We focus on the quantum mechanics of the model at past and future infinity. There is a Hilbert space of asymptotic states and an infinite-time evolution operator between the far past and far future. This evolution is not unitary, although we find that it acts unitarily on a subspace up to non-perturbative corrections. These corrections come from processes which involve changes in the spatial topology, including the nucleation of baby universes. There is significant evidence that this 1+1 dimensional model is dual to a 0+0 dimensional matrix integral in the double-scaled limit. So the bulk quantum mechanics, including the Hilbert space and approximately unitary evolution, emerge from a classical integral. We find that this emergence is a robust consequence of the level repulsion of eigenvalues along with the double scaling limit, and so is rather universal in random matrix theory.

• Research Organization: San Francisco State University, CA (United States)
• Sponsoring Organization: Fannie and John Hertz Foundation; Stanford Graduate Fellowship; USDOE Office of Science (SC)
• Grant/Contract Number: SC0013682
• OSTI ID: 1976592
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 12 Vol. 2021; ISSN 1029-8479
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English