CMB polarization features from inflation versus reionization
CMB polarization features from inflation versus reionization
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DOI：
10.1103/physrevd.79.103519
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发表时间：
2009-03
影响因子：
5
通讯作者：
M. Mortonson;C. Dvorkin;H. Peiris;Wayne Hu Kicp;U. Chicago;U. Cambridge
中科院分区：
文献类型：
--
作者：
M. Mortonson;C. Dvorkin;H. Peiris;Wayne Hu Kicp;U. Chicago;U. Cambridge
WMAP观测到的宇宙微波背景温度各向异性的角功率谱在l{approx}20处有一个异常的下降，在l{approx}40处有一个凸起。对这种结构的一种解释是原始曲率功率谱中存在的特征，可能是由暴胀势的一个步骤引起的。这些特征的检测仅从温度数据中略微显着。然而，膨胀特征假说预测了E模式偏振功率谱的特定形状，其结构类似于在l{approx}20-40 ℃温度下观察到的结构。因此，在几度尺度上测量CMB偏振可以用作假设的一致性检查。普朗克卫星具有统计灵敏度，以确认或排除最适合具有3{sigma}显著性的温度特征的模型，假设所有其他参数都已知。在宇宙方差有限的实验中，该显著性提高到8{sigma}。对于可以解释温度下降和上升的暴胀模型的测试，不确定性的主要来源是与复杂的再电离历史所产生的极化特征的混淆，这最多将普朗克的重要性降低到2.5 σ，而理想实验的重要性为5 σ-6 σ。由于在几度尺度上预期的TE相关性较低，因此用大的张量分量对偏振谱进行平滑只会略微降低偏振检验暴胀特征的能力，这就要求偏振与观测到的温度谱一致。如果极化前景可以被充分地减去，普朗克将提供支持或反对原始功率谱特征的有价值的证据。未来的高灵敏度偏振卫星将能够对特征假设进行决定性的检验，并提供关于暴胀潜力中可能步骤的形状的补充信息。«少
The angular power spectrum of the cosmic microwave background temperature anisotropy observed by WMAP has an anomalous dip at l{approx}20 and a bump at l{approx}40. One explanation for this structure is the presence of features in the primordial curvature power spectrum, possibly caused by a step in the inflationary potential. The detection of these features is only marginally significant from temperature data alone. However, the inflationary feature hypothesis predicts a specific shape for the E-mode polarization power spectrum with a structure similar to that observed in temperature at l{approx}20-40. Measurement of the CMB polarization on few-degree scales can therefore be used as a consistency check of the hypothesis. The Planck satellite has the statistical sensitivity to confirm or rule out the model that best fits the temperature features with 3{sigma} significance, assuming all other parameters are known. With a cosmic variance limited experiment, this significance improves to 8{sigma}. For tests of inflationary models that can explain both the dip and the bump in temperature, the primary source of uncertainty is confusion with polarization features created by a complex reionization history, which, at most, reduces the significance to 2.5{sigma} for Planck and 5{sigma}-6{sigma} for an ideal experiment. Smoothing of the polarizationmore » spectrum by a large tensor component only slightly reduces the ability of polarization to test for inflationary features, as does requiring that polarization is consistent with the observed temperature spectrum, given the expected low level of TE correlation on few-degree scales. If polarized foregrounds can be adequately subtracted, Planck will supply valuable evidence for or against features in the primordial power spectrum. A future high-sensitivity polarization satellite would enable a decisive test of the feature hypothesis and provide complementary information about the shape of a possible step in the inflationary potential.« less