Constraining Recent Oscillations in Quintessence Models with Euclid

TL;DR

This paper forecasts Euclid's ability to constrain oscillating quintessence dark energy models, showing that Weak Lensing will significantly outperform BAO in detecting late-time Universe oscillations.

Contribution

It introduces a Fisher matrix forecast for Euclid's capacity to detect late-time oscillations in quintessence models, highlighting the superior constraining power of Weak Lensing.

Findings

Weak Lensing constrains model parameters to 5-20% precision.

Euclid can distinguish oscillating models from non-oscillating ones.

Data could detect small late-time oscillations in the Universe's expansion.

Abstract

Euclid is a future space-based mission that will constrain dark energy with unprecedented accuracy. Its photometric component is optimized for Weak Lensing studies, while the spectroscopic component is designed for Baryon Acoustic Oscillations (BAO) analysis. We use the Fisher matrix formalism to make forecasts on two quintessence dark energy models with a dynamical equation of state that leads to late-time oscillations in the expansion rate of the Universe. We find that Weak Lensing will place much stronger constraints than the BAO, being able to discriminate between oscillating models by measuring the relevant parameters to $1\sigma$ precisions of 5 to $20\%$. The tight constraints suggest that Euclid data could identify even quite small late-time oscillations in the expansion rate of the Universe.