Dark energy models toward observational tests and data

TL;DR

This paper reviews observational tests of dark energy models, emphasizing the need for diverse data across redshifts to distinguish between competing theories of cosmic acceleration.

Contribution

It analyzes three classes of dark energy models, highlighting degeneracies and the necessity for comprehensive multi-redshift data to constrain these models.

Findings

Current data supports a flat universe with accelerated expansion.

Degeneracy among dark energy models complicates their differentiation.

More data at various redshifts is essential for model selection.

Abstract

A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision Cosmology. Despite of the quality of astrophysical surveys, the nature of dark energy dominating the matter-energy content of the universe is still unknown and a lot of different scenarios are viable candidates to explain cosmic acceleration. Methods to test these cosmological models are based on distance measurements and lookback time toward astronomical objects used as standard candles. I discuss the characterizing parameters and constraints of three different classes of dark energy models pointing out the related degeneracy problem which is the signal that more data at low (z= 0- 1), medium (1<z<10) and high (10 <z< 1000) redshift are needed to definitively select realistic models.