Cosmological implications of quantum entanglement in the multiverse

Understand

We explore the cosmological implications of quantum entanglement between two causally disconnected universes in the multiverse.

• We first consider two causally separated de Sitter spaces with a state which is initially entangled.
• We derive the reduced density matrix of our universe and compute the spectrum of vacuum fluctuations.
• We then consider the same system with an initially non-entangled state.