论文标题
来自普朗克CMB数据的宇宙学参数的定向变化
Directional Variations of Cosmological Parameters from the Planck CMB Data
论文作者
论文摘要
最近的观察结果表明，大规模的宇宙各向同性违反了宇宙原理的重要组成部分。在本文中，我们使用宇宙微波背景（CMB）数据来搜索$λ\ Mathrm {CDM} $模型中宇宙学参数的空间变化。我们适合Planck温度角功率谱$ \ MATHCAL {C}^{tt} _ \ Ell $，用于48个不同的半基，以48个不同的方向为中心，以搜索标准宇宙学参数的定向依赖性。 $ 3（2）σ$ - 级方向变化$ω_bh^2 $，$ω_CH^2 $，$ n_s $，$100θ_\ Mathrm {Mc Mc} $，$ H_0 $ $（τ$和$ \ \ ln（10^{10} {10} a_s a_s））$。此外，参数的方向分布遵循偶极子形式到良好的近似值。各向同性和各向异性假设之间的贝叶斯因子为$ 0.0041 $，强烈不利前者。 $ω_bh^2 $，$ω_ch^2 $，$ n_s $，$100θ_\ Mathrm {mc} $和$ a_s e^{ - 2τ} $通常与$ \ boldsymbol {v} \ equiv（b = equiv（b = equiv（b = equiv（b =） -5.6^{+17.0 {\ circ}} _ { - 17.4}，l = 48.8^{+14.3 {\ circ}} _ { - 14.4}）$，该$大致依赖于在良好结构常数中的变化中的二极管，大约是$ 45^{$ cird} $ cird for cird of cird for cird of cird pers for cird for cird of cird for cird percy for。偶极子，CMB平价不对称和QSO的极化。我们的结果表明，在标准CMB分析中，对宇宙原理的严重侵犯或以前未知的系统错误。
Recent observations suggest that there are violations of the isotropy of the universe at large scales, an important part of the cosmological principle. In this paper, we use the Cosmic Microwave Background (CMB) data to search for spatial variations of the cosmological parameters in the $Λ\mathrm{CDM}$ model. We fit the Planck temperature angular power spectrum $\mathcal{C}^{TT}_\ell$ for 48 different half-skies, centering on 48 different directions, to search for directional dependences of the standard cosmological parameters. There are $3(2)σ$-level directional variations in $Ω_bh^2$, $Ω_ch^2$, $n_s$, $100θ_\mathrm{MC}$, and $H_0$ $(τ$ and $\ln(10^{10}A_s))$. Furthermore, the directional distributions of the parameters follow a dipole form to good approximation. The Bayes factor between the isotropic and anisotropic hypotheses is $0.0041$, strongly disfavouring the former. The best-fit dipole axes for $Ω_bh^2$, $Ω_ch^2$, $n_s$, $100θ_\mathrm{MC}$, and $A_s e^{-2τ}$ all generally align with the mean direction of $\boldsymbol{V} \equiv (b = -5.6^{+17.0{\circ}}_{-17.4}, l = 48.8^{+14.3{\circ}}_{-14.4})$, which is roughly perpendicular to the dipole of the variation in fine structure constant, and is about $45^{\circ}$ to the directions of the CMB kinematic dipole, CMB parity asymmetry, and polarization of QSOs. Our results suggest either significant violation of the cosmological principle, or previously unknown systematic errors in the standard CMB analysis.
