A parametric model for dark energy

TL;DR

This paper introduces a new time-dependent parameterization of dark energy's equation of state, analyzing its cosmological implications and testing its viability against current observational data to better understand cosmic acceleration.

Contribution

It proposes a novel, well-behaved parametric form for dark energy's EoS over all redshifts and classifies models within the parametric plane for observational testing.

Findings

The parameterization fits current observational data well.

It distinguishes between different classes of dark energy models.

The analysis constrains the parameter space of dark energy models.

Abstract

Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology but also in high energy physics theories. Following this approach, we explore in this paper some cosmological consequences of a new time-dependent parameterization for the dark energy equation of state (EoS), which is a well behaved function of the redshift $z$ over the entire cosmological evolution, i.e., $z\in [-1,\infty)$. This parameterization allows us to divide the parametric plane $(w_0,w_1)$ in defined regions associated to distinct classes of dark energy models that can be confirmed or excluded from a confrontation with current observational data. A statistical analysis involving the most recent observations from type Ia supernovae, baryon acoustic oscillation peak, Cosmic Microwave Background shift parameter and Hubble evolution $H(z)$ is performed to check the observational viability of the EoS parameterization here proposed.