arXiv 2005.048052020-05astro-ph.CO

EFTofLSS中红移空间中具有精确时间依赖性的有偏径迹

Biased Tracers in Redshift Space in the EFTofLSS with exact time dependence

Yaniv Donath, Leonardo Senatore

备注：: 39 pages, 8 figures. v2: minor corrections, JCAP published version
发表信息：: JCAP10(2020)039
DOI：: 10.1088/1475-7516/2020/10/039

摘要：

在大尺度结构的有效场论中，研究了Einstein - de Sitter（EdS）近似对红移空间星系单圈功率谱的影响。对暗物质密度扰动和速度发散进行了精确的时间依赖性处理。将密度扰动分解为不同的时间演化，自然会产生不可约的偏差基础。然而，在EdS近似中，每次该基跨越一个7维空间，该空间是一个稍微不同的空间，并且该差异由单个可计算的时间和$\vec k$相关函数捕获。然后，我们计算红移空间星系的单圈功率谱与EdS近似（$P^{\text{EdS-approx}}$）和没有（$P^{\text{Exact}}$）。对于双极子，我们发现$P_{\text{0}}^{\text{Exact}}/P_{\text{0}}^{\text{EdS-approx}}\sim 1.003$，对于四极子$P_{\text{2}}^{\text{Exact}}/P_{\text{2}}^{\text{EdS-approx}}\sim 1.007$，在$z=0.57$处，并且在较低的红移处急剧增加。最后，我们表明，即使在允许偏置系数在物理允许的范围内移动后，仍然存在相当大一部分的效果。这表明EdS近似只能将数据拟合到与下一代宇宙学调查的精度大致相当的精度水平。此外，我们发现，实施确切的时间依赖形式主义是不苛刻的，很容易适用于数据。这两点激发了对宇宙学参数的直接研究。

英文摘要：

We study the effect of the Einstein - de Sitter (EdS) approximation on the one-loop power spectrum of galaxies in redshift space in the Effective Field Theory of Large-Scale Structure. The dark matter density perturbations and velocity divergence are treated with exact time dependence. Splitting the density perturbation into its different temporal evolutions naturally gives rise to an irreducible basis of biases. While, as in the EdS approximation, at each time this basis spans a seven-dimensional space, this space is a slightly different one, and the difference is captured by a single calculable time- and $\vec k$-dependent function. We then compute the redshift-space galaxy one-loop power spectrum with the EdS approximation ($P^{\text{EdS-approx}}$) and without ($P^{\text{Exact}}$). For the monopole we find $P_{\text{0}}^{\text{Exact}}/P_{\text{0}}^{\text{EdS-approx}}\sim 1.003$ and for the quadrupole $P_{\text{2}}^{\text{Exact}}/P_{\text{2}}^{\text{EdS-approx}}\sim 1.007$ at $z=0.57$, and sharply increasing at lower redshifts. Finally, we show that a substantial fraction of the effect remains even after allowing the bias coefficients to shift within a physically allowed range. This suggests that the EdS approximation can only fit the data to a level of precision that is roughly comparable to the precision of the next generation of cosmological surveys. Furthermore, we find that implementing the exact time dependence formalism is not demanding and is easily applicable to data. Both of these points motivate a direct study of this effect on the cosmological parameters.

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