Nonlocal bispectra from super cosmic variance
Nonlocal bispectra from super cosmic variance
复制标题
超宇宙方差的非局域双谱
DOI：
10.1103/physrevd.91.083518
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发表时间：
2015
影响因子：
5
通讯作者：
S. Shandera
中科院分区：
文献类型：
--
作者：
Bekir Baytacs;Aruna Kesavan;Elliot Nelson;Sohyun Park;S. Shandera
我们提出了非高斯统计的例子，可以诱导双谱匹配的本地和非本地（包括等边）模板在有偏见的子卷。我们发现的情况下，从耦合到长波长模式的偏置只影响功率谱，只有双谱或两者兼而有之。我们的研究结果表明，排除多场的情况是相当困难的：标量相关性的一些测量，包括双谱的形状，可以与单时钟的预测一致，即使在超视界模式的宇宙方差在工作。此外，如果密度扰动的观察排除了单时钟暴胀，那么我们在得出有关标量涨落的粒子物理起源的任何进一步结论时将面临严重的宇宙方差障碍。
We present examples of non-Gaussian statistics that can induce bispectra matching local and non-local (including equilateral) templates in biased sub-volumes. We find cases where the biasing from coupling to long wavelength modes affects only the power spectrum, only the bispectrum or both. Our results suggest that ruling out multi-field scenarios is quite difficult: some measurements of the scalar correlations, including the shape of the bispectrum, can be consistent with single-clock predictions even when cosmic variance from super-horizon modes is at work. Furthermore, if observations of the density perturbations rule out single-clock inflation, we will face a serious cosmic variance obstacle in drawing any further conclusions about the particle physics origin of the scalar fluctuations.