Non-Canonical Dark Energy Parameter Evolution in a Canonical Quintessence Cosmology

TL;DR

This paper derives analytic equations for dark energy evolution in a quintessence cosmology with a Higgs-like potential, revealing a universe that extends before the big bang and suggesting a potentially older, larger pre-bang universe.

Contribution

It provides a novel analytic solution for dark energy parameters using Lambert W functions in a quintessence model with a Higgs-like potential, including pre-bang evolution.

Findings

Analytic expressions for dark energy evolution as a function of scale factor.

The universe may have existed before the big bang, extending infinitely into the past.

The pre-bang universe describes a contraction phase leading to the big bang.

Abstract

This study considers the specific case of a flat, minimally coupled to gravity, quintessence cosmology with a dark energy quartic polynomial potential that has the same mathematical form as the Higgs potential. Previous work on this case determined that the scalar field is given by a simple expression of the Lambert W function in terms of the easily observable scale factor. This expression provides analytic equations for the evolution of cosmological dark energy parameters as a function of the scale factor for all points on the Lambert W function principal branch. The Lambert W function is zero at a scale factor of zero that marks the big bang. The evolutionary equations beyond the big bang describe a canonical universe that is similar to {\Lambda}CDM, making it an excellent dynamical template to compare with observational data. The portion of the W function principal before the big bang extends to the infinite pre-bang past. It describes a noncanonical universe with an initially very low mass density that contracts by rolling down the dark energy potential to a singularity, big bang, at the scale factor zero point. This provides a natural origin for the big bang. It also raises the possibility that the universe existed before the big bang and is far older, and that it was once far larger than its current size. The recent increasing interest in the possibility of a dynamical universe instead of {\Lambda}CDM makes the exploration of the nature of such universes particularly relevant.