Quantum Discord in de-Sitter Axiverse

TL;DR

This paper investigates quantum discord in a de Sitter Axiverse setting, revealing that quantum correlations persist even when entanglement disappears, with implications for understanding quantum effects in cosmological models.

Contribution

It introduces a novel calculation of quantum discord in a 3+1 dimensional de Sitter Axiverse, linking quantum correlations to cosmological parameters.

Findings

Quantum discord remains non-zero even when entanglement vanishes.

Increasing curvature reduces quantum entanglement between regions.

Quantum discord persists across different observer frames in de Sitter space.

Abstract

In this work, we compute quantum discord between two causally independent areas in $3+1$ dimensions global de Sitter Axiverse to investigate the signs of quantum entanglement. For this goal, we study a bipartite quantum field theoretic setting driven by an Axiverse that arises from the compactification of Type IIB strings on a Calabi-Yau three fold. We consider a spherical surface that separates the interior and exterior causally unconnected subregions of the spatial slice of the global de Sitter space. The Bunch-Davies state is the most straightforward initial quantum vacuum that may be used for computing purposes. Two observers are introduced, one in an open chart of de Sitter space and the other in a global chart. The observers calculate the quantum discord generated by each detecting a mode. The relationship between an observer in one of the two Rindler charts in flat space and another in a Minkowski chart is comparable to this circumstance. We see that when the curvature of the open chart increases, the state becomes less entangled. Nevertheless, we see that even in the limit when entanglement vanishes, the quantum discord never goes away.