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arXiv 2406.09545astro-ph.CO
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广义相对论中的全天球傅里叶-贝塞尔功率谱

The full-sky Spherical Fourier-Bessel power spectrum in general relativity

Federico Semenzato, Daniele Bertacca, Alvise Raccanelli

AI总结:

本研究提出纳入所有投影与相对论效应、无需Limber近似的全天球傅里叶-贝塞尔形式体系,发现忽略相对论修正会系统性偏差非高斯性参数估计,还提出可搜寻相对论修正信号的跨区间相关性方案。

摘要:

我们提出了一种在光锥上利用球傅里叶-贝塞尔(Spherical Fourier-Bessel,SFB)形式体系的两点相关性分析星系成团性的形式体系,该体系是解释所有广角效应和相对论(GR)效应的天然选择。我们拓展了先前的研究,纳入了所有投影效应和GR效应,开发了一种高效的数值实现方案,该方案避免使用Limber近似,包含多区间相关性和完整的非对角协方差。\n 利用该形式体系,我们研究了忽略GR修正的影响,尤其是这会给非高斯性参数$f_\mathrm{NL}$的测量带来多大偏差。\n 我们的结果表明,不纳入相对论投影项会对$f_\mathrm{NL}$的估计值产生系统性且不可忽略的偏差。具体结果取决于巡天规格和星系族的性质,但我们强调这种偏差通常都会存在。\n 最后,我们提出了一种新的跨区间相关性方案,可用于搜寻相对论修正的清晰信号,并表明这需要使用3D全天区形式体系。

英文摘要:

We present a formalism for analyzing galaxy clustering on the lightcone with the 2-point correlation in the Spherical Fourier-Bessel (SFB) formalism, which is a natural choice to account for all wide-angle and relativistic (GR) effects. We extend previous studies by including all projection and GR effects, developing an efficient numerical implementation that avoids the use of the Limber approximation, includes multi-bins correlations and a full non-diagonal covariance. Using this formalism, we investigate the impact of neglecting GR corrections, and in particular how much this could bias measurements of the non-Gaussianity parameter $f_\mathrm{NL}$. Our results show that not including relativistic projection terms can systematically and non-negligibly bias estimates of $f_\mathrm{NL}$. The exact results depend on survey specifications and galaxy population properties, but we stress that a bias will generally be present. Finally, we develop a novel prescription for cross-bin correlations that allow to search for a clean signal of relativistic corrections, and show that this requires the use of the 3D full-sky formalism.

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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