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arXiv 2005.06325astro-ph.CO
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利用相位相关约束结构增长率

Constraining the growth rate of structure with phase correlations

Joyce Byun, Felipe Oliveira Franco, Cullan Howlett, Camille Bonvin, Danail Obreschkow

备注：
28 pages, 13 figures, 2 tables. v2 has additional discussion on model-independence of the forecasts. v3 matches the MNRAS accepted version
发表信息：
MNRAS 497, 1765 (2020)
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AI总结：

该研究提出利用红移空间星系密度场的线相关函数多极矩补充功率谱，以打破 f 与 σ8 的简并，并预测其可显著提升 DESI、Euclid 的约束精度。

摘要：

我们证明，红移空间中星系密度场各相位之间的相关性，能够提供关于大尺度结构增长率的额外信息，并与功率谱多极矩形成互补。具体而言，我们考察了线相关函数（LCF）的多极矩，该函数关联三个共线点之间的相位；并采用 Fisher 预测方法表明，LCF 多极矩可以打破大尺度上功率谱多极矩中存在的结构增长率 f 测量与扰动振幅 σ8 之间的简并。对于 DESI 和 Euclid 等下一代星系巡天，在红移 z=0.25 时，相对于仅使用功率谱测量，这可使 f 和 σ8 的测量在 kmax=0.15 h Mpc−1 时最高改善 220%，在 kmax=0.30 h Mpc−1 时最高改善 50%。在 kmax=0.15 h Mpc−1 时，对平均红移 z̄=0.25 的 DESI BGS 样本，f 和 σ8 约束的平均改善约为 90%；对 z̄=1.25 的 DESI ELG 样本约为 40%；对 z̄=1.3 的 Euclid Hα 星系约为 40%。在 kmax=0.30 h Mpc−1 时，DESI BGS 样本的平均改善约为 40%，而 DESI ELG 和 Euclid Hα 星系均约为 20%。

英文摘要：

We show that correlations between the phases of the galaxy density field in redshift space provide additional information about the growth rate of large-scale structure that is complementary to the power spectrum multipoles. In particular, we consider the multipoles of the line correlation function (LCF), which correlates phases between three collinear points, and use the Fisher forecasting method to show that the LCF multipoles can break the degeneracy between the measurement of the growth rate of structure $f$ and the amplitude of perturbations $σ_8$ that is present in the power spectrum multipoles at large scales. This leads to an improvement in the measurement of $f$ and $σ_8$ by up to 220 per cent for $k_{\rm max} = 0.15 \, h\mathrm{Mpc}^{-1}$ and up to 50 per cent for $k_{\rm max} = 0.30 \, h\mathrm{Mpc}^{-1}$ at redshift $z=0.25$, with respect to power spectrum measurements alone for the upcoming generation of galaxy surveys like DESI and Euclid. The average improvements in the constraints on $f$ and $σ_8$ for $k_{\rm max} = 0.15 \, h\mathrm{Mpc}^{-1}$ are $\sim 90$ per cent for the DESI BGS sample with mean redshift $\overline{z}=0.25$, $\sim 40$ per cent for the DESI ELG sample with $\overline{z}=1.25$, and $\sim 40$ per cent for the Euclid H$α$ galaxies with $\overline{z}=1.3$. For $k_{\rm max} = 0.30 \, h\mathrm{Mpc}^{-1}$, the average improvements are $\sim 40$ per cent for the DESI BGS sample and $\sim 20$ per cent for both the DESI ELG and Euclid H$α$ galaxies.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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