Entanglement of self interacting scalar fields in an expanding spacetime

TL;DR

This paper investigates how self-interactions in scalar fields influence quantum correlations and entanglement in an expanding spacetime, revealing insights into the interplay between quantum field theory and cosmological evolution.

Contribution

It provides a detailed analysis of self-interaction effects on quantum correlations in scalar fields within an expanding universe, a novel exploration in quantum field theory in curved spacetime.

Findings

Self-interactions modify quantum entanglement between modes.

Quantum correlations encode information about spacetime evolution.

The study enhances understanding of quantum fields in cosmological backgrounds.

Abstract

We evaluate self-interaction effects on the quantum correlations of field modes of opposite momenta for scalar $\lambda \phi^4$ theory in a two-dimensional asymptotically flat Robertson-Walker spacetime. Such correlations are encoded both in the von-Neumann entropy defined through the reduced density matrix in one of the modes and in the covariance expressed in terms of the expectation value of the number operators for each mode in the evolved state. The entanglement between field modes carries information about the underlying spacetime evolution.