2016/12/28 by Sugumi Kanno, Misao Sasaki, Takahiro Tanaka · 1 citation
Physics and Astronomy · #hep-th #gr-qc #quant-ph
paper · pdf · doi:10.1007/jhep03(2017)068
published as JHEP 1703 (2017) 068 · 22 pages, 2 figures
arxiv created 2016/12/28 · arxiv updated 2017/05/22
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.