Quintessence models with an oscillating equation of state and their potentials

• 来源期刊: 中国物理（英文版）
• 关键词: quintessence equation of state
• 年，卷（期）: 2007,（9）
• 页码范围: 2830-2836
• 页数: 7页
• 语种: 英文

摘要

In this paper, we investigate the quintessence models with an oscillating equation of state (EOS) and its potentials.From the constructed potentials, which have an EOS of ωφ = ω0 + ω1 sin z, we find that they are all the oscillating functions of the field φ, and the oscillating amplitudes decrease (or increase) with φ. From the evolutive equation of the field φ, we find that this is caused by the expansion of the universe. This also makes it very difficult to build a model whose EOS oscillates forever. However one can build a model with EOS oscillating for a certain period of time. Then we discuss three quintessence models, which are the combinations of the invert power law functions and the oscillating functions of the field φ. We find that they all follow the oscillating EOS.