Cosmic Expansion via Axion-Induced Quintessence

TL;DR

This paper models dark energy using a scalar field influenced by axion potentials, exploring its dynamics, effects of the cosmological constant, and implications for cosmic structure and observations.

Contribution

It introduces a novel scalar field model for dark energy with axion potential, incorporating inhomogeneous scale factors and screening mechanisms for cosmological parameters.

Findings

Analogous pendulum dynamics for scalar field

Cosmological constant acts like a spring constant

Inhomogeneous scale factor relates to CMB fluctuations

Abstract

In this paper, dark energy is modelled via a spherically symmetric quintessence scalar field $\varphi$, the dynamics of which are found to be analogous to a pendulum. This is due to a driving axion potential $V(\left|\varphi\right|)$, whose origins reside within the study of quantum chromodynamics (QCD). The effect of a cosmological constant $\Lambda$, introduced to represent the vacuum energy of space, is also investigated. Preliminary results suggest that $\Lambda$ is analogous to a spring-constant, and thus determining the elasticity of space. Additionally, a cosmological scale-factor $a(t,r)$, notably with an added spatial dependence, is also considered. We propose that due to this inhomogeneous scale-factor, the energy-density is characteristic of temperature fluctuations observed within the cosmic microwave background. Such fluctuations could ultimately lead to a universe composed of filaments and voids; vast expanses of space, separated by regions of localised matter/energy-density. Finally, we provide a means of screening both the cosmological constant and curvature of the universe, to effective values that are more consistent with experimental observation.