Reconstructing the Primordial Spectrum from WMAP Data by the Cosmic Inversion Method
Reconstructing the Primordial Spectrum from WMAP Data by the Cosmic Inversion Method
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DOI：
10.1086/383339
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发表时间：
2003-09
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影响因子：
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通讯作者：
N. Kogo;Makoto Matsumiya;M. Sasaki;J. Yokoyama
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文献类型：
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作者：
N. Kogo;Makoto Matsumiya;M. Sasaki;J. Yokoyama
利用最近发展起来的宇宙反演方法，从威尔金森微波各向异性探测器（WMAP）的观测数据中重建了曲率扰动P（k）的原始谱。与传统的参数拟合方法相比，我们的方法可以很好地再现P（k）中的小特征。结果得到了一个复杂的振荡P（k）。我们证实，这个重建的P（k）恢复WMAP角功率谱的分辨率高达Δ 1 × 5。然而，在使用人工宇宙微波背景数据的模拟中也发现了类似的振荡特征，这些数据是从具有随机误差的标度不变P（k）模拟观测产生的。为了研究非平凡特征的统计意义，包括振荡行为，因此，我们考虑一种方法来量化尺度不变性的偏差，并将其应用于从WMAP数据重建的P（k）。我们发现在k = 1.5 × 10-2和2.6 × 10-2 Mpc-1附近可能存在偏离标度不变性的情况。
We reconstruct the primordial spectrum of the curvature perturbation, P(k), from the observational data of the Wilkinson Microwave Anisotropy Probe (WMAP) by the cosmic inversion method developed recently. In contrast to conventional parameter-fitting methods, our method can potentially reproduce small features in P(k) with good accuracy. As a result, we obtain a complicated oscillatory P(k). We confirm that this reconstructed P(k) recovers the WMAP angular power spectrum with resolution up to Δl ≃ 5. Similar oscillatory features are found, however, in simulations using artificial cosmic microwave background data generated from a scale-invariant P(k) with random errors that mimic observation. In order to examine the statistical significance of the nontrivial features, including the oscillatory behaviors, therefore, we consider a method to quantify the deviation from scale invariance and apply it to the P(k) reconstructed from the WMAP data. We find that there are possible deviations from scale invariance around k ≃ 1.5 × 10-2 and 2.6 × 10-2 Mpc-1.