论文标题
反对使用$ h^{ - 1} {\ rm mpc} $单位的论点
Arguments against using $h^{-1}{\rm Mpc}$ units in observational cosmology
论文作者
论文摘要
通常以$ h^{ - 1} {\ rm mpc} $的单位表示宇宙学测量。在这里，我们回顾了这种习惯起源的一些并发症。这些单位引起的一个关键问题与物质功率谱的归一化有关，这通常以线性理论RMS质量波动为特征，而半径为$ 8 \，h^{ - 1} {\ rm mpc} $，$σ_8$。该参数无法正确捕获$ h $对密度波动振幅的影响。我们表明，$σ_8$的使用引起了关于低红色shift探针和宇宙微波背景数据之间一致性的所谓$σ_8$张力的严重误解，以及通常表达从红移空间扭曲中推断出的增长率估计的方式。 We propose to abandon the use of $h^{-1}{\rm Mpc}$ units in cosmology and to characterize the amplitude of the matter power spectrum in terms of $σ_{12}$, defined as the mass fluctuation in spheres of radius $12\,{\rm Mpc}$, whose value is similar to the standard $σ_8$ for $h\sim 0.67 $。
It is common to express cosmological measurements in units of $h^{-1}{\rm Mpc}$. Here, we review some of the complications that originate from this practice. A crucial problem caused by these units is related to the normalization of the matter power spectrum, which is commonly characterized in terms of the linear-theory rms mass fluctuation in spheres of radius $8\,h^{-1}{\rm Mpc}$, $σ_8$. This parameter does not correctly capture the impact of $h$ on the amplitude of density fluctuations. We show that the use of $σ_8$ has caused critical misconceptions for both the so-called $σ_8$ tension regarding the consistency between low-redshift probes and cosmic microwave background data, and the way in which growth-rate estimates inferred from redshift-space distortions are commonly expressed. We propose to abandon the use of $h^{-1}{\rm Mpc}$ units in cosmology and to characterize the amplitude of the matter power spectrum in terms of $σ_{12}$, defined as the mass fluctuation in spheres of radius $12\,{\rm Mpc}$, whose value is similar to the standard $σ_8$ for $h\sim 0.67$.
