A note on initial state entanglement in inflationary cosmology
Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU Apdo. 644, 48080 Bilbao, Spain and IKERBASQUE, Basque Foundation for Science - Maria Diaz de Haro 3, 48013, Bilbao, Spain
Received: 13 August 2015
Accepted: 16 September 2015
We give a new interpretation of the effect of initial state entanglement on the spectrum of vacuum fluctuations. We consider an initially entangled state between two free massive scalar fields in de Sitter space. We construct the initial state by making use of a Bogoliubov transformation between the Bunch-Davies vacuum and a four-mode squeezed state, and then derive the exact power spectrum for one of the scalar fields. We demonstrate that an oscillatory spectrum hardly appears for the initially entangled state unless an ad hoc absolute value of the Bogoliubov coefficients is chosen.
PACS: 04.62.+v – Quantum fields in curved spacetime / 98.80.-k – Cosmology
© EPLA, 2015