# Quantum discord in de Sitter space

@article{Kanno2016QuantumDI, title={Quantum discord in de Sitter space}, author={Sugumi Kanno and Jonathan P. Shock and J. Soda}, journal={Physical Review D}, year={2016}, volume={94}, pages={125014} }

We study quantum discord between two free modes of a massive scalar field in a maximally entangled state in de Sitter space. We introduce two observers, one in a global chart and the other in an open chart of de Sitter space, and the observers determine the quantum discord created by each detecting one of the modes. This situation is analogous to the relationship between an observer in a Minkowski chart and another in one of the two Rindler charts in flat space. We find that the state becomes…

## 28 Citations

Quantum Correlations in de Sitter Space

- Physics
- 2017

We study quantum correlation of a massive scalar field in a maximally entangled state in de Sitter space. We prepare two observers, one in a global chart and the other in an open chart of de Sitter…

Quantum steering for continuous variable in de Sitter space

- Physics
- 2019

We study the distribution of quantum steerability for continuous variables between two causally disconnected open charts in de Sitter space. It is shown that quantum steerability suffers from "sudden…

Vacuum state of the Dirac field in de Sitter space and entanglement entropy

- Physics
- 2016

A bstractWe compute the entanglement entropy of a free massive Dirac field between two causally disconnected open charts in de Sitter space. We first derive the Bunch-Davies vacuum mode functions of…

Quantum entanglement in de Sitter space from stringy axion: An analysis using α vacua

- PhysicsNuclear Physics B
- 2019

Abstract In this work, we study the phenomena of quantum entanglement by computing de Sitter entanglement entropy from von Neumann measure. For this purpose we consider a bipartite quantum field…

Real-space entanglement in the Cosmic Microwave Background

- PhysicsJournal of Cosmology and Astroparticle Physics
- 2021

We compute the entanglement entropy, mutual information and quantum discord of the Cosmic Microwave Background (CMB) fluctuations in real space. To that end, we first show that measurements of these…

Generation of genuine tripartite entanglement for continuous variables in de Sitter space

- Physics
- 2020

Abstract We study the distribution of quantum entanglement for continuous variables among causally disconnected open charts in de Sitter space. It is found that genuine tripartite entanglement is…

Fermionic vacua and entanglement in hyperbolic de Sitter spacetime

- Physics
- 2018

We point out a non-trivial feature of the vacuum structure of free massive or massless Dirac fields in the hyperbolic de Sitter spacetime. Here we have two causally disconnected regions, say $R$ and…

Vacuum state in de Sitter spacetime with static charts

- PhysicsPhysical Review D
- 2018

We study the free massive scalar field in de Sitter spacetime with static charts. In particular, we find positive-frequency modes for the Bunch-Davies vacuum state natural to the static charts as…

Dirac fermion, cosmological event horizons, and quantum entanglement

- Physics
- 2020

We discuss the field quantisation of a free massive Dirac fermion in the two causally disconnected static patches of the de Sitter spacetime, by using mode functions that are normalisable on the…

Quantum Entanglement in the Multiverse

- Physics
- 2017

In this report, we consider cosmological implications of quantum entanglement between two causally disconnected universes in the multiverse. Supposing that our universe was initially entangled with a…

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