The Limits on Cosmological Anisotropies and Inhomogeneities from COBE Data
The Limits on Cosmological Anisotropies and Inhomogeneities from COBE Data
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COBE 数据对宇宙学各向异性和不均匀性的限制
DOI：
10.1086/303633
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Tim Gebbie
中科院分区：
文献类型：
--
作者：
W. Stoeger;M. Araújo;Tim Gebbie
假定宇宙学原理成立，Maarten，Ellis和Stoeger(MES)最近构建了一个详细的方案，将宇宙背景辐射(CMB)中的各向异性与宇宙大尺度结构中的各向异性和不均匀联系起来，并展示了如何简单地使用CMB四极和八极极限来限制这些各向异性和不均匀。首先，我们指出并讨论了MES格式中使用的温度各向异性的协变多阶矩与COBE的四极和八极结果之间的联系。然后，我们将这些结果引入到MES极限方程中，以获得关于各向异性和非均匀的完整的宇宙学测量集合的确定的定量极限。我们发现，在不受膨胀率H影响的情况下，所有的各向异性度量都小于10-4，而在有膨胀率H的情况下，所有的各向异性度量都小于10-6mpc-1。这些结果定量地证明了可观测宇宙确实在最大尺度上接近Friedmann-Lemaütre-Robertson-Walker(FLRW)，并且可以用几乎-FLRW模型来建模--也就是说，在最大尺度上表征可观测宇宙的各向异性和不均匀性不太大而不能被认为是对FLRW的扰动。
Assuming that the cosmological principle holds, Maartens, Ellis, & Stoeger (MES) recently constructed a detailed scheme linking anisotropies in the cosmic background radiation (CMB) with anisotropies and inhomogeneities in the large-scale structure of the universe and showed how to place limits on those anisotropies and inhomogeneities simply by using CMB quadrupole and octupole limits. First, we indicate and discuss the connection between the covariant multiple moments of the temperature anisotropy used in the MES scheme and the quadrupole and octupole results from COBE. Then we introduce those results into the MES limit equations to obtain definite quantitative limits on the complete set of cosmological measures of anisotropy and inhomogeneity. We find that all the anisotropy measures are less than 10-4 in the case of those not affected by the expansion rate H and less than 10-6 Mpc-1 in the case of those which are. These results demonstrate quantitatively that the observable universe is indeed close to Friedmann-Lemaître-Robertson-Walker (FLRW) on the largest scales and can be modeled adequately by an almost-FLRW model—that is, the anisotropies and inhomogeneities characterizing the observable universe on the largest scales are not too large to be considered perturbations to FLRW.