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arXiv 1809.08779astro-ph.COhep-phquant-ph
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CMB各向异性和非高斯性分析的熵方法

Entropy methods for CMB analysis of anisotropy and non-Gaussianity

Momchil Minkov, Marvin Pinkwart, Peter Schupp

摘要:

我们提出了几个伪熵的措施,同意与威尔熵,但显着更快的计算。所有这些都是旋转不变的措施纠缠非常敏感的非高斯性,各向异性和统计依赖的球谐系数。我们提供了一个简单的证明,投影伪熵收敛到Wehrl熵的辅助投影空间的维数增加。此外,对于$l=2$,我们证明了Wehrl熵和角赝熵都可以表示为多极矢量弦距平方的函数.我们还表明,角赝熵可以区分高斯和非高斯温度波动在大多极,并从此提供了一个非蛮力识别非高斯性的方法。这使我们能够使用普朗克2015/2018和WMAP 7年数据研究CMB中统计各向异性和非高斯性的可能暗示,直到多极$l=1000$。我们发现,$l=5$和$28$在$2$处有很大的熵-- $3σ$的意义和一个关于这与宇宙偶极子的联系的轻微暗示。在更大范围的大角度尺度上,我们没有发现各向同性/高斯违反的迹象。我们还发现了一个小规模的范围,$l\in[895,905]$,这是不相容的假设在约$3σ$水平,虽然有多少这种意义可以减少考虑到选择效应是一个悬而未决的问题。我们在对2015年和2018年数据的分析中发现了总体相似的结果。最后,我们还演示了如何范围的角动量可以研究范围的角赝熵。我们的主要目的是介绍这些方法,分析它们的数学背景,并展示它们的用途,为该领域的研究人员提供一个额外的工具。

英文摘要:

We propose several pseudoentropy measures that agree well with the Wehrl entropy, but are significantly faster to compute. All of them are rotationally invariant measures of entanglement very sensitive to non-Gaussianity, anisotropy, and statistical dependence of spherical harmonic coefficients. We provide a simple proof that the projection pseudoentropy converges to the Wehrl entropy with increasing dimensionality of the ancilla projection space. Furthermore, for $l=2$, we show that both the Wehrl entropy and the angular pseudoentropy can be expressed as functions of the squared chordal distance of multipole vectors. We also show that the angular pseudoentropy can distinguish between Gaussian and non-Gaussian temperature fluctuations at large multipoles and henceforth provides a non-brute-force method for identifying non-Gaussianities. This allows us to study possible hints of statistical anisotropy and non-Gaussianity in the CMB up to multipole $l=1000$ using Planck 2015/2018, and WMAP 7-yr data. We find that $l=5$ and $28$ have a large entropy at $2$--$3σ$ significance and a slight hint towards a connection of this with the cosmic dipole. On a wider range of large angular scales we do not find indications of isotropy/Gaussianity violation. We also find a small-scale range, $l\in[895,905]$, that is incompatible with the assumptions at about $3σ$ level, although how much this significance can be reduced by taking into account the selection effect is left as an open question. We find overall similar results in our analysis of the 2015 and the 2018 data. Finally, we also demonstrate how a range of angular momenta can be studied with the range angular pseudoentropy. Our main purpose is to introduce the methods, analyze their mathematical background, and demonstrate their usage for providing researchers in this field with an additional tool.

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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