Quintessence models with an oscillating equation of state and their potentials

Quintessence models with an oscillating equation

of state and their potentials

Zhao Wen

【期刊名称】《中国物理：英文版》 【年(卷),期】2007(016)009

【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. 【总页数】7页(2830-2836)

【关键词】quintessence, equation of state 【作者】Zhao Wen

【作者单位】Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310014, China