Tensors, BICEP2 results, prior dependence, and dust
Tensors, BICEP2 results, prior dependence, and dust
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DOI：
10.1103/physrevd.92.063511
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发表时间：
2014-09
影响因子：
5
通讯作者：
Marina Cortês;A. Liddle;D. Parkinson
中科院分区：
文献类型：
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作者：
Marina Cortês;A. Liddle;D. Parkinson
我们调查的先验依赖于推断的光谱的原始张量扰动，根据最近的结果从BICEP 2，并考虑到可能的尘埃贡献的偏振各向异性。我们强调张量功率谱的优化参数化，并通过其幅度AT的对数先验，导致在枢轴尺度变化下更均匀地变换的结果。在没有前景的情况下，BICEP 2和普朗克的结果之间的紧张关系使得张量谱指数nT在联合分析中是蓝色倾斜的，这与标准的暴胀预测（nT<0）相矛盾。当前景占，BICEP 2的结果不再需要非标准的通货膨胀参数区域。我们提出的限制原始AT和nT，采用前景的情况下提出的Mortonson和Seljak和普朗克353 GHz的观测，并评估什么灰尘的贡献留下了可检测的宇宙学信号。我们发现，如果有足够的尘埃信号与标准的通货膨胀兼容，那么原始信号太弱，被BICEP 2鲁棒检测到，如果普朗克+WMAP上限温度和E-模式偏振是正确的。
We investigate the prior dependence on the inferred spectrum of primordial tensor perturbations, in light of recent results from BICEP2 and taking into account a possible dust contribution to polarized anisotropies. We highlight an optimized parametrization of the tensor power spectrum, and adoption of a logarithmic prior on its amplitude AT, leading to results that transform more evenly under change of pivot scale. In the absence of foregrounds the tension between the results of BICEP2 and Planck drives the tensor spectral index nT to be blue tilted in a joint analysis, which would be in contradiction to the standard inflation prediction (nT<0). When foregrounds are accounted for, the BICEP2 results no longer require nonstandard inflationary parameter regions. We present limits on primordial AT and nT, adopting foreground scenarios put forward by Mortonson and Seljak and motivated by Planck 353 GHz observations, and assess what dust contribution leaves a detectable cosmological signal. We find that if there is sufficient dust for the signal to be compatible with standard inflation, then the primordial signal is too weak to be robustly detected by BICEP2 if Planck+WMAP upper limits from temperature and E-mode polarization are correct.