Dark energy from entanglement entropy

TL;DR

This paper proposes that dark energy arises from quantum entanglement and decoherence in the universe, linking quantum information concepts to cosmological acceleration without requiring a cosmological constant.

Contribution

It introduces a model connecting quantum entanglement entropy with dark energy, providing a quantum-based explanation for cosmic acceleration compatible with observations.

Findings

Models reproduce current cosmic acceleration without a cosmological constant.

Entanglement entropy can mimic dark energy effects.

Two cosmic volume cases yield viable equations of state.

Abstract

We show that quantum decoherence, in the context of observational cosmology, can be connected to the cosmic dark energy. The decoherence signature could be characterized by the existence of quantum entanglement between cosmological eras. As a consequence, the Von Neumann entropy related to the entanglement process, can be compared to the thermodynamical entropy in a homogeneous and isotropic universe. The corresponding cosmological models are compatible with the current observational bounds being able to reproduce viable equations of state without introducing {\it a priori} any cosmological constant. In doing so, we investigate two cases, corresponding to two suitable cosmic volumes, $V\propto a^3$ and $V\propto H^{-3}$, and find two models which fairly well approximate the current cosmic speed up. The existence of dark energy can be therefore reinterpreted as a quantum signature of entanglement, showing that the cosmological constant represents a limiting case of a more complicated model derived from the quantum decoherence.