Abstract.
Inflation is often argued to generate quantum entanglement between cosmological perturbations with opposite wavenumbers. This appears to be in tension with the standard treatment of cosmological perturbations, in which their quantum state is replaced by a classical probability distribution, thereby eliminating all quantum effects.
In this talk, I will argue that this tension can be alleviated by examining how entanglement is distributed among local observables accessible within our universe. I will show that although each local degree of freedom becomes entangled with the rest of the field, this entanglement is highly delocalized. This delocalization effectively acts as noise for entanglement among observables localized within the observable universe, and naturally contributes to explaining the apparent classicality of cosmological perturbations.
(The slides will be available here)