DARK VISCOUS FLUID DESCRIBED BY A UNIFIED EQUATION OF STATE IN COSMOLOGY
DARK VISCOUS FLUID DESCRIBED BY A UNIFIED EQUATION OF STATE IN COSMOLOGY
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DOI：
10.1142/s0218271807010821
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发表时间：
2006-04
影响因子：
2.2
通讯作者：
Jie Ren;Xin-he Meng
中科院分区：
文献类型：
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作者：
Jie Ren;Xin-he Meng
我们通过引入统一的 EOS 来描述建模为暗粘性流体的宇宙内容来推广 ΛCDM 模型，其动机是单个常数状态方程 (EOS) p = -p0 (p0 > 0) 精确地再现了 ΛCDM 模型。该EOS在独特的框架中描述了完美的流体项、耗散效应和宇宙常数，并且可以解析求解弗里德曼方程。特别是，我们发现了 EOS 参数与标量场的可重整化条件之间的关系。我们开发了一种完全数值方法来执行 χ2 最小化，以直接从 Friedmann 方程约束宇宙学模型中的参数，并使用 SNe 数据和从 SDSS 数据测量的参数 $\mathcal{A}$ 来约束我们的模型。结果表明，在晚期宇宙中，耗散效应相当小。
We generalize the ΛCDM model by introducing a unified EOS to describe the Universe contents modeled as dark viscous fluid, motivated by the fact that a single constant equation of state (EOS) p = -p0 (p0 > 0) reproduces the ΛCDM model exactly. This EOS describes the perfect fluid term, the dissipative effect, and the cosmological constant in a unique framework and the Friedmann equations can be analytically solved. Especially, we find a relation between the EOS parameter and the renormalizable condition of a scalar field. We develop a completely numerical method to perform a χ2 minimization to constrain the parameters in a cosmological model directly from the Friedmann equations, and employ the SNe data with the parameter $\mathcal{A}$ measured from the SDSS data to constrain our model. The result indicates that the dissipative effect is rather small in the late-time Universe.