Spacetime anisotropy affects cosmological entanglement

TL;DR

This paper investigates how spacetime anisotropy influences quantum entanglement in the universe, extending prior isotropic models by analyzing anisotropic effects and their potential to reveal cosmological features.

Contribution

It introduces a decomposition of entanglement entropy into isotropic and anisotropic parts, demonstrating the significance of anisotropy in cosmological entanglement studies.

Findings

Anisotropic contributions to entanglement are non-negligible.

Entanglement can potentially be used to infer universe features.

Analysis includes models with weak and conformal coupling.

Abstract

Most existing cosmological entanglement studies are focused on the isotropic Robertson-Walker (RW) spacetime. Here we go beyond this limitation and study the influence of anisotropy on entanglement generated by dynamical spacetime. Since the isotropic spacetime is viewed as a background medium and the anisotropy is incorporated as perturbation, we decompose entanglement entropy into isotropic and anisotropic contributions. The latter is shown to be non-negligible by analyzing two cosmological models with weak and conformal coupling. We also show the possibility of using entanglement to infer about universe features.