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arXiv 0908.3197astro-ph.CO
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约束暗流体

Constraining the dark fluid

Martin Kunz, Andrew R Liddle, David Parkinson, Changjun Gao

摘要:

宇宙学观测通常是在假设暗区可以分解为暗物质和暗能量两部分的情况下进行拟合的。然而,只要探测器保持纯粹的引力,就没有唯一的分解,观测只能限制一种暗流体;这被称为暗简并。我们使用观察直接约束这种暗流体在一个独立的模型的方式,特别是证明,数据不能拟合的暗流体与一个单一的常数状态方程。通过在尺度因子$a$中选择不同的多项式来参数化暗流体状态方程,并利用当前的运动学数据来约束参数。虽然对暗流体的最简单解释仍然是它由单独的暗物质和宇宙学常数贡献组成,但我们的结果涵盖了其他模型类型,包括统一的暗能量/物质场景。

英文摘要:

Cosmological observations are normally fit under the assumption that the dark sector can be decomposed into dark matter and dark energy components. However, as long as the probes remain purely gravitational, there is no unique decomposition and observations can only constrain a single dark fluid; this is known as the dark degeneracy. We use observations to directly constrain this dark fluid in a model-independent way, demonstrating in particular that the data cannot be fit by a dark fluid with a single constant equation of state. Parameterizing the dark fluid equation of state by a variety of polynomials in the scale factor $a$, we use current kinematical data to constrain the parameters. While the simplest interpretation of the dark fluid remains that it is comprised of separate dark matter and cosmological constant contributions, our results cover other model types including unified dark energy/matter scenarios.

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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