AI 中文总结
研究局部宇宙空洞对平坦$w_0w_a$CDM 宇宙学中哈勃率低红移测量的影响，用流体动力学模型计算空洞引起的哈勃位移，发现其主要受物质部分控制，局部低密度能影响哈勃率推断，但无法解决哈勃张力。
AI 中文摘要
我们研究了局部宇宙空洞对平坦$w_0w_a$CDM 宇宙学中哈勃率低红移测量的影响。使用孤立球形反顶帽低密度的流体动力学模型，计算空洞引起的哈勃位移作为红移、封闭密度对比度$\delta_{\rm E}$和宇宙学参数的函数。发现该效应主要由物质部分通过$\delta_{\rm E}$和$\Omega_{\rm m,0}$控制，动态暗能量仅给出次要的晚期修正。对于普朗克校准的$\Lambda$CDM 背景，匹配 SH0ES 值需要当前空洞$\delta_{\rm E}(z = 0)\simeq -0.44$，比类似 KBC 的局部低密度深得多。类似 KBC 的空洞将 SH0ES - 普朗克差异降低到约$2\sigma$，但深度不足以完全调和这两个测量值。考虑动态暗能量，包括近期 DES 和 DESI 分析所涉及的区域，仅在百分之几的水平上改变结果。还表明，局部推断的$H_0$值报告的红移依赖性可以由有效的封闭物质分布从现象学上表示。这种重建应解释为局部结构效应的一致性检验，而不是对$H_0$演化背景值的解释。总体而言，局部低密度会影响低红移哈勃率推断，但在此处考虑的球形空洞设置内不能解决哈勃张力。
英文摘要
We investigate the effect of local cosmic voids on low-redshift measurements of the Hubble rate in flat $w_0w_a$CDM cosmologies. Using a hydrodynamical model for isolated spherical inverse top-hat underdensities, we compute the void-induced Hubble shift as a function of redshift, enclosed density contrast $δ_{\rm E}$ and cosmological parameters. We find that the effect is mainly controlled by the matter sector, through $δ_{\rm E}$ and $Ω_{\rm m,0}$, while dynamical dark energy gives only subdominant late-time corrections. For a Planck-calibrated $Λ$CDM background, matching the SH0ES value requires a present-day void with $δ_{\rm E}(z=0)\simeq -0.44$, substantially deeper than the KBC-like local underdensity. A KBC-like void lowers the SH0ES-Planck discrepancy to about $2σ$, but is not deep enough to fully reconcile the two measurements. Allowing for dynamical dark energy, including regions motivated by recent DES and DESI analyses, changes this result only at the percent level. We also show that the reported redshift dependence of locally inferred $H_0$ values can be represented phenomenologically by an effective enclosed matter profile. This reconstruction should be interpreted as a consistency test of local-structure effects rather than as explanation for an evolving background value of $H_0$. Overall, local underdensities can affect low-redshift Hubble-rate inferences, but they do not resolve the Hubble tension within the spherical void setup considered here.
Comments22 pages, 11 figures
