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Title: Entanglement entropy and decoupling in the Universe

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1413562
Grant/Contract Number:
SC0013607
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 96; Journal Issue: 12; Related Information: CHORUS Timestamp: 2017-12-15 10:32:00; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Nakai, Yuichiro, Shiba, Noburo, and Yamada, Masaki. Entanglement entropy and decoupling in the Universe. United States: N. p., 2017. Web. doi:10.1103/PhysRevD.96.123518.
Nakai, Yuichiro, Shiba, Noburo, & Yamada, Masaki. Entanglement entropy and decoupling in the Universe. United States. doi:10.1103/PhysRevD.96.123518.
Nakai, Yuichiro, Shiba, Noburo, and Yamada, Masaki. 2017. "Entanglement entropy and decoupling in the Universe". United States. doi:10.1103/PhysRevD.96.123518.
@article{osti_1413562,
title = {Entanglement entropy and decoupling in the Universe},
author = {Nakai, Yuichiro and Shiba, Noburo and Yamada, Masaki},
abstractNote = {},
doi = {10.1103/PhysRevD.96.123518},
journal = {Physical Review D},
number = 12,
volume = 96,
place = {United States},
year = 2017,
month =
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on December 15, 2018
Publisher's Accepted Manuscript

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  • We investigate the entropy evolution in the early universe by computing the change of the entanglement entropy in Freedmann-Robertson-Walker quantum cosmology in the presence of particle horizon. The matter is modeled by a Chaplygin gas so as to provide a smooth interpolation between inflationary and radiation epochs, rendering the evolution of entropy from early time to late time trackable. We found that soon after the onset of the inflation, the total entanglement entropy rapidly decreases to a minimum. It then rises monotonically in the remainder of the inflation epoch as well as the radiation epoch. Our result is in qualitativemore » agreement with the area law of Ryu and Takayanagi including the logarithmic correction. We comment on the possible implication of our finding to the cosmological entropy problem.« less
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  • We consider oscillators evolving subject to a periodic driving force that dynamically entangles them, and argue that this gives the linearized evolution around periodic orbits in a general chaotic Hamiltonian dynamical system. We show that the entanglement entropy, after tracing over half of the oscillators, generically asymptotes to linear growth at a rate given by the sum of the positive Lyapunov exponents of the system. These exponents give a classical entropy growth rate, in the sense of Kolmogorov, Sinai and Pesin. We also calculate the dependence of this entropy on linear mixtures of the oscillator Hilbert-space factors, to investigate themore » dependence of the entanglement entropy on the choice of coarse graining. We find that for almost all choices the asymptotic growth rate is the same.« less