# Imprints of an extended Chevallier-Polarski-Linder parametrization on the large scale of our universe

## TL;DR

This paper introduces an extended Chevallier-Polarski-Linder dark energy parametrization, analyzing its effects on the universe's large-scale structure and comparing it with the standard $\\Lambda$CDM model using current astronomical data.

## Contribution

It develops a higher-order extension of the CPL parametrization and assesses its observational viability against the standard cosmological model.

## Key findings

- All models favor a quintessence-like dark energy.
- Phantom crossing is marginally allowed within 68% confidence level.
- Bayesian analysis favors the standard $\Lambda$CDM model over the extended parametrizations.

## Abstract

In the present work we perform a systematic analysis of a new dark energy parametrization and its various corrections at first and higher orders around the presence epoch $z=0$, where the first order correction of this dark energy parametrization recovers the known Chevallier-Polarski-Linder model. We have considered up to the third order corrections of this parametrization and investigate the models at the level of background and perturbations. The models have been constrained using the latest astronomical datasets from a series of potential astronomical data, such as the cosmic microwave background observations, baryon acoustic oscillations measurements, recent Pantheon sample of the supernova type Ia and the Hubble parameter measurements. From the analyses we found that all parametrization favor the quintessential character of the dark energy equation of state where the phantom crossing is marginally allowed (within 68\% CL). Finally, we perform the Bayesian analysis using \texttt{MCEvidence} to quantify the statistical deviations of the parametrizations compared to the standard $\Lambda$CDM cosmology. The Bayesian analysis reports that $\Lambda $CDM is favored over all the DE parametrizations.