Abstract
We study the effect of a bubble wall on the entanglement entropy of a free massive scalar field between two causally disconnected open charts in de Sitter space. We assume there is a delta-functional wall between the open charts. This can be thought of as a model of pair creation of bubble universes in de Sitter space. We first derive the Euclidean vacuum mode functions of the scalar field in the presence of the wall in the coordinates that respect the open charts. We then derive the Bogoliubov transformation between the Euclidean vacuum and the open chart vacua that makes the reduced density matrix diagonal. We find that larger walls lead to less entanglement. Our result may be regarded as evidence of decoherence of bubble universes from each other. We also note an interesting relationship between our results and discussions of the black hole firewall problem.
Highlights
Quantum entanglement has fascinated many physicist because of its counterintuitive nature
We study the effect of a bubble wall on the entanglement entropy of a free massive scalar field between two causally disconnected open charts in de Sitter space
They showed that the entanglement entropy, which is a measure of quantum entanglement, of a free massive scalar field between two disconnected open charts is nonvanishing
Summary
Quantum entanglement has fascinated many physicist because of its counterintuitive nature. Exponentially, any two mutually separated regions eventually become causally disconnected This is most conveniently described by spanning open universe coordinates on two open charts in de Sitter space. Quantum entanglement between two causally disconnected regions in de Sitter space was first studied by Maldacena and Pimentel [4]. They showed that the entanglement entropy, which is a measure of quantum entanglement, of a free massive scalar field between two disconnected open charts is nonvanishing. Inflation leads to an “initial state” of the Universe following inflation that is highly entangled This invites the question of whether compelling observational evidence for the entangled nature of the initial density fluctuations can be found.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have