Geometric corrections to cosmological entanglement

TL;DR

This paper explores how inhomogeneous geometric perturbations in the universe influence quantum entanglement, revealing that geometry can significantly affect entanglement entropy and potentially relate to dark matter.

Contribution

It introduces a perturbative analysis of entanglement production caused by geometric effects in cosmology, highlighting the role of geometric (quasi)-particles as dark matter candidates.

Findings

First-order entropy oscillations due to perturbations

Second-order mode-mixing from geometric effects

Quantification of geometric contribution to entanglement

Abstract

We investigate entanglement production by inhomogeneous perturbations over a homogeneous and isotropic cosmic background, demonstrating that the interplay between quantum and geometric effects can have relevant consequences on entanglement entropy, with respect to homogeneous scenarios. To do so, we focus on a conformally coupled scalar field and discuss how geometric production of scalar particles leads to entanglement. Perturbatively, at first order we find oscillations in entropy correction, whereas at second order the underlying geometry induces mode-mixing on entanglement production. We thus quantify entanglement solely due to geometrical contribution and compare our outcomes with previous findings. We characterize the geometric contribution through geometric (quasi)-particles, interpreted as dark matter candidates.