Effects of the quantum vacuum at a cosmic scale and of dark energy

TL;DR

This paper explores how quantum vacuum fluctuations may contribute to the accelerated expansion of the universe, suggesting a possible quantum origin for dark energy effects.

Contribution

It introduces a semi-classical Einstein equation approach incorporating quantum vacuum effects into cosmological models, expanding in powers of G.

Findings

Quantum vacuum contributes to second order in Einstein equations.

Part of cosmic acceleration may be due to quantum vacuum fluctuations.

Provides a semi-classical framework linking quantum effects to dark energy.

Abstract

The Einstein equation in a semi-classical approximation is applied to a spherical region of the universe, with the stress-energy tensor consisting of the mass density and pressure of the LambdaCDM cosmological model plus an additional contribution of the quantum vacuum. Expanding the equation in powers of Newton constant G, the vacuum contributes to second order. The result is that at least a part of the acceleration in the expansion of the universe may be due to the quantum vacuum fluctuations