Dark energy as an elastic strain fluid

TL;DR

This paper proposes a novel interpretation of dark energy as an elastic strain caused by a cosmic defect, which modifies the universe's expansion and fits observational data well.

Contribution

It introduces a new elastic strain fluid model for dark energy, linking cosmic defects to the universe's accelerated expansion.

Findings

Model reproduces observational data effectively

Strain parameters are of the order 10^{-52} m^{-2}

Tracks radiation early and mimics a cosmological constant later

Abstract

The origin of the accelerated expansion of the universe is still unclear and new physics is needed on cosmological scales. We propose and test a novel interpretation of dark energy as originated by an elastic strain due to a cosmic defect in an otherwise Euclidean space-time. The strain modifies the expansion history of the universe. This new effective contribution tracks radiation at early times and mimics a cosmological constant at late times. The theory is tested against observations, from nucleosynthesis to the cosmic microwave background and formation and evolution of large scale structure to supernovae. Data are very well reproduced with Lam\'e parameters of the order of 10^{-52} m^{-2}.