Observational constraints on the averaged universe
Observational constraints on the averaged universe
复制标题
平均宇宙的观测限制
DOI：
10.1103/physrevd.85.043506
复制
发表时间：
2012
影响因子：
5
通讯作者：
Clarkson C
中科院分区：
文献类型：
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作者：
Clarkson C
由于广义相对论的广义协方差和爱因斯坦方程的非线性，在广义相对论中求平均是一项复杂的操作。后者确保了在宇宙尺度上平滑时空不会产生与求解物质分布平滑的爱因斯坦方程相同的结果，并且我们适合观测的平滑模型不需要简单地与实际的时空几何有关。这样做的一个具体结果是，度规中的几何空间曲率项与弗里德曼方程中的动态空间曲率项脱钩。在这里，我们通过对哈勃太空望远镜(HST)、CMB、Ia型超新星(SNIa)和重子声振荡(BaO)数据集的拟合来研究这种去耦合的后果。我们发现，只有几何空间曲率受到严格约束，在我们彻底理解宇宙学中的平均问题之前，我们约束暗能量动力学的能力将受到严重损害。
Averaging in general relativity is a complicated operation, due to the general covariance of the theory and the nonlinearity of Einstein’s equations. The latter of these ensures that smoothing spacetime over cosmological scales does not yield the same result as solving Einstein’s equations with a smooth matter distribution, and that the smooth models we fit to observations need not be simply related to the actual geometry of spacetime. One specific consequence of this is a decoupling of the geometrical spatial curvature term in the metric from the dynamical spatial curvature in the Friedmann equation. Here we investigate the consequences of this decoupling by fitting to a combination of Hubble Space Telescope (HST), CMB, type Ia supernovae (SNIa), and baryon acoustic oscillation (BAO) data sets. We find that only the geometrical spatial curvature is tightly constrained and that our ability to constrain dark energy dynamics will be severely impaired until we gain a thorough understanding of the averaging problem in cosmology.
DOI：
--
发表时间：
2006
期刊：
--
影响因子：
--
作者：
Iroon Polytechniou-
通讯作者：
Iroon Polytechniou-