Pure Natural Quintessential Inflation and Dark Energy

TL;DR

This paper introduces a natural inflation model inspired by Witten's conjecture, where the axion-Yang-Mills coupling modifies the potential, successfully explaining both early universe inflation and late-time dark energy within a unified framework.

Contribution

The model uniquely combines natural inflation with a quintessence field derived from axion-Yang-Mills interactions, providing a unified explanation for inflation and dark energy.

Findings

Compatible with current CMB data

Provides a dynamical dark energy consistent with observed density

Unifies inflation and dark energy in a single model

Abstract

We propose the pure natural quintessential inflation model which is motivated by Witten's conjecture, where the axion couples to pure Yang-Mills $SU(N)$ gauge field at large N limit. This modifies the standard cosine potential which is presented in the natural inflation, making it compatible with current CMB data. Our model gives a successful inflation as well as acceleration at the late times by quintessence inflaton field($\phi$). Here the inflaton field is responsible for inflation, after that the field enters into peculiar type of reheating and then they act as dynamical dark energy field which follows the same inflation potential and same model parameters. The dynamical field slowly rolls until the Hubble drops to mass of the quintessence field and it reaches the current dark energy field value. Here the dark energy scale is field dependent. Our quintessence model follows thawing frozen approach therefore the frozen quintessence field evolves with respect to cosmic time from initial field value($\phi_{i}$) to present non-zero minimum field value($\phi_{0}$). The obtained field value turned into ultra-light and it satisfies the present dark energy density which is $V(\phi_{0}) \approx \Lambda_{\text{DE}}^{4} = (2.3 \times 10^{-3}\text{eV})^{4}$.