Entanglement between two scalar fields in an expanding spacetime

TL;DR

This paper investigates how two interacting scalar fields maintain quantum entanglement during cosmic expansion, revealing that their mutual interaction preserves quantum correlations and encodes information about the spacetime.

Contribution

It demonstrates that mutual interactions between scalar fields sustain quantum entanglement in an expanding universe, highlighting potential observable effects.

Findings

Quantum correlations survive smooth expansion at lowest order in coupling

Interacting fields encode more information about spacetime

Quantum entanglement persists due to mutual interactions

Abstract

We study the evolution of the two scalar fields entangled via a mutual interaction in an expanding spacetime. We compute the logarithmic negativity to leading order in perturbation theory and show that for lowest order in the coupling constants, the mutual interaction will give rise to the survival of the quantum correlations in the limit of the smooth expansion. The results suggest that interacting fields can codify more information about the underlying expansion spacetime and lead to interesting observable effects.