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

Sugumi Kanno, Misao Sasaki, Takahiro Tanaka

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)


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 m2/H2 becomes small, and the difference is maximal in the massless limit.

Original languageEnglish
Article number68
JournalJournal of High Energy Physics
Issue number3
Publication statusPublished - Mar 1 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics


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