A New Class of Parametrization for Dark Energy without Divergence

TL;DR

This paper introduces a novel, non-divergent parametrization of dark energy's equation of state that remains well-behaved throughout cosmic evolution, and constrains its simplest models using current observational data.

Contribution

It proposes a new class of dark energy parametrizations that avoid divergence issues and applies observational constraints to these models.

Findings

The new parametrization remains finite during the entire cosmic evolution.

Observational data favor certain parameter ranges for the proposed models.

The models fit well with supernova, CMB, and BAO data.

Abstract

In this paper, we propose a new class of parametrization of the equation of state of dark energy. In contrast with the famous CPL parametrization, these new parametrization of the equation of state does not divergent during the evolution of the Universe even in the future. Also, we perform a observational constraint on two simplest dark energy models belonging to this new class of parametrization, by using the Markov Chain Monte Carlo (MCMC) method and the combined latest observational data from the type Ia supernova compilations including Union2(557), cosmic microwave background, and baryon acoustic oscillation.