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arXiv 1012.4459astro-ph.COgr-qchep-th
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宇宙学暗区的统一模型

Unified models of the cosmological dark sector

W Zimdahl, W S Hipólito-Ricaldi, H E S Velten

摘要:

我们模型的宇宙底层的粘性流体,这是应该提供一个统一的描述黑暗的部门和无压重子物质。在均匀各向同性背景下,该混合气体的\textit{total}能量密度表现为广义Chaubergin气体。这种能量密度的扰动本质上是非绝热的,并且是源相对熵扰动。由此得到的重子物质功率谱与2dFGRS和SDSS(DR7)数据一致。联合统计分析,也使用哈勃函数和超新星Ia数据,表明,与其他研究不同,存在一个最大的概率分布为负的减速参数的现值$q_{0} \approx - 0.53$。此外,与其他方法不同,这里提出的统一模型更倾向于一个由大爆炸核合成所建议的重子物质丰度的数量级的物质含量。

英文摘要:

We model the cosmological substratum by a viscous fluid that is supposed to provide a unified description of the dark sector and pressureless baryonic matter. In the homogeneous and isotropic background the \textit{total} energy density of this mixture behaves as a generalized Chaplygin gas. The perturbations of this energy density are intrinsically non-adiabatic and source relative entropy perturbations. The resulting baryonic matter power spectrum is shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also Hubble-function and supernovae Ia data, shows that, different from other studies, there exists a maximum in the probability distribution for a negative present value $q_{0} \approx - 0.53$ of the deceleration parameter. Moreover, different from other approaches, the unified model presented here favors a matter content that is of the order of the baryonic matter abundance suggested by big-bang nucleosynthesis.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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