Entanglement Entropy of de Sitter Space \alpha-Vacua
  We generalize the analysis of arXiv:1210.7244 to de Sitter space \alpha-vacua and compute the entanglement entropy of a free scalar for the half-sphere at late time. 
Norihiro Iizuka, Toshifumi Noumi, Noriaki Ogawa
hep-th