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

TLDR: In this paper, the SO(1, 1) scalar field model of dark energy was proposed and the Lagrangian may be decomposed as that of the real quintessence model and 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.

Abstract: We suggest the SO(1, 1) scalar field model of dark energy. In this model, the Lagrangian may be decomposed as that of the real quintessence model and 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 kinetics model of the universe with time-dependent power, which can describe the universe transition from ordinary acceleration to super acceleration. We also give a simple discussion of the Big Rip, singularity, and point out the possibility that the universe driven by a phantom avoids it.