标题： 物质偶极子和由于大波长扰动引起的哈勃张力 显示英文标题

标题： Matter Dipole and Hubble Tension due to Large Wavelength Perturbations

摘要： 我们理论上分析了来自CatWISE2020目录的类星体分布中观察到的偶极各向异性。目录数据显示在$z\approx 1$附近有一个峰值，表明存在一个大尺度的偶极分量。我们探讨了这种偶极子可能是由在CMB解耦时超出视界但在之后进入视界并变成亚视界的原始密度涨落模式驱动的可能性。特别地，我们考虑了具有波数范围为$(10^{-4} - 4 \times 10^{-3})~\mathrm{Mpc}^{-1} $的绝热模式的影响，这些模式对应的波长尺度为几吉帕秒（Gpc），即$k$。这些模式可以产生大尺度的密度变化，很可能导致物质分布中的各向异性，从而影响观测到的类星体的数密度。我们还证明了一个共动波数为$k\lesssim0.3H_0$的超视界曲率扰动模式，可以导致局部推断的哈勃常数显著增强。这一效应为本地测量和CMB推断的$H_0$之间的观测差异提供了一个合理的解释。 显示英文摘要

摘要： We theoretically analyze the dipole anisotropy observed in the quasar distribution from the CatWISE2020 catalog. The catalog data shows a peak around $z\approx 1$, suggesting the presence of a large-scale dipole component. We explore the possibility that this dipole could be driven by primordial density fluctuations from modes that were superhorizon at the time of CMB decoupling but have since entered the horizon and become subhorizon. In particular, we consider the impact of adiabatic modes with wavenumbers $k$ in the range $(10^{-4} - 4 \times 10^{-3})~\mathrm{Mpc}^{-1} $, corresponding to wavelength scales of several Gpc. Such modes can create large-scale density variations, likely causing anisotropies in the distribution of matter and, as a result, affecting the number density of observed quasars. We also demonstrate that a superhorizon curvature perturbations mode, with comoving wavenumber $k\lesssim0.3H_0$ can lead to a significant enhancement in the locally inferred Hubble constant. This effect offers a viable explanation for the observed discrepancy between local and CMB inferred measurements of $H_0$.