Universal signature of quantum entanglement across cosmological distances

Abstract

Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that entanglement between the modes of the fluctuating field plays in its observable predictions. In this paper, we import techniques from quantum information theory to reveal hitherto undiscovered predictions for inflation which, in turn, signals how quantum entanglement across cosmological scales can affect large scale structure. Our key insight is that observable long-wavelength modes must be part of an open quantum system, so that the quantum fluctuations can decohere in the presence of an environment of short-wavelength modes. By assuming the simplest model of single-field inflation, and considering the leading order interaction term from the gravitational action, we derive a universal lower bound on the observable effect of such inescapable entanglement.

8 pages + 10 pages (Appendix); comments welcome

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Cited by in corpus (21)

• Minimal decoherence from inflation
• The warm inflation story
• The Open Effective Field Theory of Inflation
• Quantum corrections to the primordial tensor spectrum: Open EFTs & Markovian decoupling of UV modes
• Cosmic Purity Lost: Perturbative and Resummed Late-Time Inflationary Decoherence
• Decoherence out of fire: Purity loss in expanding and contracting universes
• The Early Universe as an Open Quantum System: Complexity and Decoherence
• In-in formalism for the entropy of quantum fields in curved spacetimes
• Dilaton-induced open quantum dynamics
• An Open Effective Field Theory for light in a medium
• Real-space quantum-to-classical transition of time dependent background fluctuations
• Quantum thermodynamics of de Sitter space
• Superhorizon entanglement from inflationary particle production
• Density matrix formalism for interacting quantum fields
• A Flat Space Analogue for the Quantum Origin of Structure
• Open system dynamics in interacting quantum field theories
• Entanglement and correlations between local observables in de Sitter spacetime
• Entanglement entropy evolution during gravitational collapse
• Violation of Bell inequalities from Cosmic Microwave Background data
• On the Role of Fiducial Structures in Minisuperspace Reduction and Quantum Fluctuations in LQC
• Unification of Stochastic and Quantum Thermodynamics in Scalar Field Theory via a Model with Brownian Thermostat