$B$-sure. 第二部分：散射变换作为从CMB观测中检测张量-标量比的鲁棒性测试
$B$-sure. Part II. Scattering transforms as robustness test for tensor-to-scalar ratio detection from CMB observations
- International School for Advanced Studies (SISSA)（国际高等研究院）
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）
- Institute for Fundamental Physics of the Universe (IFPU)（宇宙基础物理研究所）
- Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité（巴黎高等师范学院物理实验室）
- Laboratoire de Physique des 2 infinis Irène Joliot-Curie (IJCLab), Université Paris-Saclay, CNRS/IN2P3（伊雷娜·约里奥-居里双无限物理实验室）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
提出一种基于散射变换的鲁棒性测试方法，用于识别CMB B-模探测中前景残差导致的张量-标量比偏差，在90%模拟中可检测到10^-3量级偏差，为LiteBIRD实验提供验证工具。
AI中文摘要：
银河系前景辐射是对宇宙微波背景极化观测中原始$B$-模测量的主要污染源。即使在应用了分量分离算法之后，前景残差仍可能使张量-标量比$r$的估计产生偏差，从而导致虚假探测。在本工作中，我们提出了一种鲁棒性测试方法，用于验证未来类似LiteBIRD的卫星实验所获得的原始$B$-模的最终探测结果。该测试的目标是通过寻找盲分量分离算法恢复的CMB $B$-模图中的非高斯特性来识别前景残差污染。我们采用散射变换（ST）作为对前景残差的非高斯特征及其与前景示踪图相关性敏感的汇总统计量。我们在具有不同前景复杂度水平的逼真天空模拟上对方法进行了表征和验证。所提出的测试能够在约90%的模拟中识别出张量-标量比$\gtrsim 10^{-3}$的偏差，该偏差值与LiteBIRD目标精度同数量级。此外，对于我们的特定实验配置，当偏差低于$r$参数的灵敏度时，测试通过且不发出警告。这些结果为开发验证未来宇宙学参数测量免受前景污染影响的统计工具迈出了重要一步。
英文摘要：
Galactic foregrounds represent a major contamination to the measurement of primordial $B$-modes from observations of the Cosmic Microwave Background polarisation. Even after the application of component separation algorithms, foreground residuals may potentially still bias the estimate of the tensor-to-scalar ratio $r$, causing a false detection. In this work, we present the methodology of a robustness test for the validation of an eventual detection of primordial $B$-modes, as obtained by a future, LiteBIRD-like satellite experiment. The goal of the test is to identify the foreground residuals contamination by looking for non-Gaussian properties in the CMB $B$-modes map, recovered through blind component separation algorithms. We adopt scattering transforms (ST) as our summary statistics sensitive to the non-Gaussian features of foreground residuals and to their correlation with foregrounds tracer maps. We characterise and validate the methodology on realistic sky simulations with different levels of foregrounds complexity. The proposed test is able to identify a bias on the tensor-to-scalar ratio of $\gtrsim 10^{-3}$ in $\sim 90\%$ of our simulations, with this bias value being of the same order of the accuracy targeted by LiteBIRD. Additionally, for our particular experimental configuration, the test is passed when the bias is lower than the sensitivity on the $r$ parameter, and no warning is raised. These results provide an important step forward in the development of statistical tools for validating future measurement of cosmological parameters, against foregrounds contamination.
