论文标题
局部原始非高斯和超级样本差异
Local Primordial Non-Gaussianities and Super-Sample Variance
论文作者
论文摘要
波长大于星系调查的体积的波动会影响调查本身中星系功率谱的测量。在存在局部原始非高斯（PNG）的情况下，除了超级样本的物质密度和潮汐波动之外，大规模的重力电势还引起了观察到的功率谱的调节。在这项工作中，我们首次计算红移星系功率谱对长波长引力电位的存在，从而对这种调制进行了调制，从而充分考虑了随机贡献。对于有偏见的示踪剂，由于密度，速度和重力场的小尺度波动之间的耦合，新的响应函数，后者通过比例依赖性偏置算子以及大尺度的重力潜力。我们研究了超级样本模式对局部形状原始双光谱振幅的测量的影响，$ f _ {\ rm nl}^{\ rm loc} $，核算长期模态的信号和星系动力的协方差的调制。考虑到类似DESI的调查规范，我们表明，在大多数情况下，超级样本模式很少或没有降解，实际上可以减少$ f _ {\ rm nl}^{\ rm nl}^{\ rm loc} $的错误级，而（10-30）\％，如果有偏见参数的外部信息，则可以减少。
Fluctuations with wavelengths larger than the volume of a galaxy survey affect the measurement of the galaxy power spectrum within the survey itself. In the presence of local Primordial Non- Gaussianities (PNG), in addition to the super-sample matter density and tidal fluctuations, the large-scale gravitational potential also induces a modulation of the observed power spectrum. In this work we investigate this modulation by computing for the first time the response of the redshift-space galaxy power spectrum to the presence of a long wavelength gravitational potential, fully accounting for the stochastic contributions. For biased tracers new response functions arise due to couplings between the small-scale fluctuations in the density, velocity and gravitational fields, the latter through scale dependent bias operators, and the large-scale gravitational potential. We study the impact of the super-sample modes on the measurement of the amplitude of the primordial bispectrum of the local-shape, $f_{\rm NL}^{\rm loc}$, accounting for modulations of both the signal and the covariance of the galaxy power spectrum by the long modes. Considering DESI-like survey specifications, we show that in most cases super-sample modes cause little or no degradation of the constraints, and could actually reduce the errorbars on $f_{\rm NL}^{\rm loc}$ by (10 - 30)\%, if external information on the bias parameters is available.
