Dark energy as a large scale quantum gravitational phenomenon

TL;DR

This paper proposes that dark energy arises from quantum gravitational effects of ultra-light particles within a novel STM-based quantum gravity framework, linking dark energy to quantum phenomena and suggesting a new dark matter candidate.

Contribution

It introduces a quantum gravity model where dark energy results from STM atoms and predicts ultra-light particles as dark energy and dark matter candidates.

Findings

Dark energy can be explained as a quantum gravitational effect of STM atoms.

An ultra-light particle of about 10^{-33} eV/c^2 accounts for observed dark energy.

A dark matter candidate with mass around 10^{-12} eV/c^2 is proposed.

Abstract

In our recently proposed quantum theory of gravity, the universe is made of `atoms' of space-time-matter (STM). Planck scale foam is composed of STM atoms with Planck length as their associated Compton wave-length. The quantum dispersion and accompanying spontaneous localisation of these STM atoms amounts to a cancellation of the enormous curvature on the Planck length scale. However, an effective dark energy term arises in Einstein equations, of the order required by current observations on cosmological scales. This happens if we propose an extremely light particle having a mass of about $10^{-33} \ {\rm eV/c^2}$, forty-two orders of magnitude lighter than the proton. The holographic principle suggests there are about $10^{122}$ such particles in the observed universe. Their net effect on space-time geometry is equivalent to dark energy, this being a low energy quantum gravitational phenomenon. In this sense, the observed dark energy constitutes evidence for quantum gravity. We then invoke Dirac's large number hypothesis to also propose a dark matter candidate having a mass halfway (on the logarithmic scale) between the proton and the dark energy particle, i.e. about $10^{-12}\ {\rm eV/c^2}$.