Note on Dark Energy and Cosmic Transit in a scale-invariance cosmology

TL;DR

This paper investigates scale-invariance cosmological models to understand dark energy and cosmic transition, revealing persistent negative pressure and singularities that challenge their viability.

Contribution

It introduces three toy models within scale-invariance cosmology to analyze dark energy behavior and cosmic transition, highlighting their limitations and comparing with other models.

Findings

Cosmic transit occurs in all models.

Pressure remains negative throughout evolution.

Models exhibit singularities in the equation of state.

Abstract

In general, the laws of physics are not invariant under a change of scale. To find out whether the 'scale-invariance hypothesis' corresponds to nature or not, a careful examination to its implications is required. As a consequence, the scale-invariance cosmological models need to be carefully checked with many tests in order to confirm or disconfirm them. In this paper, three different toy models have been introduced in the framework of a scale-invariance cosmology to examine dark energy and cosmic transit. Although cosmic transit exists in the three models, the pressure stays always negative during cosmic evolution. In addition, there is always a singularity in the evolution of the equation of state parameter which is not suitable for a complete investigation of dark energy evolution. The undesirable features of the parameters have been discussed, and a comparison with other cosmological contexts has been done.