SO(1,1) dark energy model and the universe transition

TL;DR

This paper introduces an SO(1,1) symmetric scalar dark energy model that allows for a broader equation of state range and describes universe transitions from acceleration to super acceleration.

Contribution

It presents a novel scalar dark energy model with SO(1,1) symmetry that overcomes negative kinetic energy issues and models universe transition dynamics.

Findings

Model extends the range of dark energy equation of state parameter w.

Allows description of universe transitioning from acceleration to super acceleration.

Provides a power-law expansion model with time-dependent parameters.

Abstract

We suggest a scalar model of dark energy with the SO(1,1) symmetry. The model may be reformulated in terms of a real scalar field $\Phi$ and the scale factor $a$ so that the Lagrangian may be decomposed as that of the real quintessence model plus the negative coupling energy term of $\Phi$ to $a$. The existence of the coupling term $L^c$ leads to a wider range of $w_{\Phi}$ and overcomes the problem of negative kinetic energy in the phantom universe model. We propose a power-law expansion model of univese with time-dependent power, which can describe the phantom universe and the universe transition from ordinary acceleration to super acceleration.