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Vacuum state of the Dirac field in de Sitter space and entanglement entropy

  • Sugumi KannoEmail author
  • Misao Sasaki
  • Takahiro Tanaka
Open Access
Regular Article - Theoretical Physics

Abstract

We compute the entanglement entropy of a free massive Dirac field between two causally disconnected open charts in de Sitter space. We first derive the Bunch-Davies vacuum mode functions of the Dirac field. We find there exists no supercurvature mode for the Dirac field. We then give the Bogoliubov transformation between the Bunch-Davies vacuum and the open chart vacua that makes the reduced density matrix diagonal. We find that the Dirac field becomes more entangled than a scalar field as m 2 /H 2 becomes small, and the difference is maximal in the massless limit.

Keywords

Classical Theories of Gravity Effective Field Theories 

Notes

Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

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Copyright information

© The Author(s) 2017

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Department of Theoretical Physics and History of ScienceUniversity of the Basque CountryBilbaoSpain
  2. 2.IKERBASQUE, Basque Foundation for ScienceBilbaoSpain
  3. 3.Center for Gravitational Physics, Yukawa Institute for Theoretical PhysicsKyoto UniversityKyotoJapan
  4. 4.Department of PhysicsKyoto UniversityKyotoJapan

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