Dark energy towards observational tests and data

TL;DR

This paper reviews the observational evidence for dark energy and discusses the challenges in distinguishing between different models due to degeneracies, emphasizing the need for diverse redshift data to identify the true nature of cosmic acceleration.

Contribution

It highlights the importance of multi-redshift data in testing dark energy models and discusses the degeneracy problem in current observational methods.

Findings

Current data supports a flat universe with accelerated expansion.

Degeneracy in models requires more comprehensive redshift observations.

Different dark energy scenarios remain viable due to observational limitations.

Abstract

A huge amount of good quality 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 excellent 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. The related degeneracy problem is the signal that more data at low 0<z<1, medium 1<z<10 and high 10 <z< 1000 redshift are needed to definitively select realistic models.