A coupled generalized three-form dark energy model

TL;DR

This paper proposes a coupled dark energy model using a generalized three-form field, analyzes its dynamical behavior, and tests it against cosmological observations, finding it can address the coincidence problem and exhibits phantom crossing.

Contribution

It introduces a novel coupled three-form dark energy model with specific power-law functions and demonstrates its viability through observational data fitting.

Findings

The model has a stable attractor and a tracking saddle point.

Best fit parameters suggest the effective dark energy EOS crosses -1.

The model can alleviate the coincidence problem.

Abstract

A coupled dark energy model is considered, in which dark energy is represented by a generalized three-form field and dark matter by dust. By assuming the functions $N$ and $I$ in the model's Lagrangian as two power-law functions of the three-form field, we obtain two fixed points of the autonomous system of evolution equations, consisting of a attractor and a tracking saddle point which can be used to alleviate the coincidence problem. After marginalizing the present three-form field $\kappa X_{0}$ which is unable to be strictly restricted, we confront the model with the latest Type Ia Supernova (SN \uppercase\expandafter{\romannumeral1}a), Baryon Acoustic Oscillations (BAO) and Cosmic Microwave Backround (CMB) radiation observations with the fitting results $\Omega_{m0}= 0.280_{-0.048}^{+0.048}$ and $\lambda=0.011_{-0.032}^{+0.032}$ in the $2\sigma$ confidence level, we also find that the best fitting effective dark energy equation of state (EOS) crosses $ -1$ at redshift around 0.2.