Cubic anomalies in the Wilkinson Microwave Anisotropy Probe
Cubic anomalies in the Wilkinson Microwave Anisotropy Probe
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威尔金森微波各向异性探头中的立方异常
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
J. Magueijo
中科院分区：
文献类型：
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作者：
K. Land;J. Magueijo
我们对Wilkinson微波各向异性探测器第一年的数据进行了双谱分析。我们发现在L 200之前有明显的信号支配，与高斯主义基本一致，除了以下特征。在L=32-62的范围内的同一双谱的L分量中有一个平坦的斑块(即低X2区)；这可以被解释为在99.6%的置信度水平下排除了高斯。在99%的置信度水平上，南北L间双谱成分也存在不对称性。优选的不对称轴与文献中引用的功率谱不对称性和三点相关函数的(L，b)=(57，10)方向有很好的相关性。然而，我们对四极杆(其双谱和主轴)的分析未能与先前声称的异常联系起来。
We perform a frequentist analysis of the bispectrum of the Wilkinson Microwave Anisotropy Probe first-year data. We find clear signal domination up to l 200, with overall consistency with Gaussianity, except for the following features. There is a flat patch (i.e. a low X 2 region) in the same-l components of the bispectrum spanning the range l = 32-62; this may be interpreted as ruling out Gaussianity at the 99.6 per cent confidence level. There is also an asymmetry between the north and south inter-l bispectrum components at the 99 per cent confidence level. The preferred asymmetry axis correlates well with the (l, b) = (57, 10) direction quoted in the literature for asymmetries in the power spectrum and three-point correlation function. However, our analysis of the quadrupole (its bispectrum and principal axes) fails to make contact with previously claimed anomalies.