Cosmic Microwave Background (CMB) photons can undergo resonant conversion into axions in the presence of magnetized plasma distributed inside non-linear large-scale structure (LSS). This process leads to axion-induced patchy screening: secondary temperature and polarization ani­sotropies with a characteristic non-blackbody frequency dependence that are strongly correlated with the distribution of LSS along our past light cone. We compute the axion-induced patchy screening contribution to two- and three- point correlation functions that include CMB anisotropies and tracers of LSS within the halo model. We use these results to forecast the sensitivity of existing and future surveys to photon-axion couplings for axion masses between 2 × 10^-13 eV and 3 × 10^-12 eV, using a combination of empirical estimates from Planck data of the contribution from instrumental noise and foregrounds as well as modeled contributions on angular scales only accessible with future datasets. We demonstrate that an analysis using Planck and the unWISE galaxy catalogue would be complementary to the most sensitive existing astrophysical axion searches, probing couplings as small as 3 × 10^-12 GeV^-1, while observations from a future survey such as CMB-S4 could extend this reach by almost an additional order of magnitude.

中文翻译：

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轴子诱导的宇宙微波背景斑片筛选


宇宙微波背景 （CMB） 光子可以在分布在非线性大尺度结构 （LSS） 内的磁化等离子体存在的情况下发生共振转化为轴子。这个过程导致轴子诱导的斑片筛选：次级温度和偏振各向异性，具有特征性的非黑体频率依赖性，与 LSS 沿我们过去的光锥分布密切相关。我们计算轴子诱导的斑片筛选对两点和三点相关函数的贡献，其中包括 CMB 各向异性和光晕模型中 LSS 的示踪剂。我们使用这些结果来预测现有和未来调查对 2 × ^10-13 eV 和 3 × ^10-12 eV 之间的轴子质量的光子-轴子耦合的敏感性，结合使用普朗克数据的经验估计仪器噪声和前景的贡献以及仅在未来数据集中才能访问的角度尺度上的建模贡献。我们证明，使用普朗克和 unWISE 星系目录的分析将与现有最敏感的天体物理轴子搜索相辅相成，探测小至 3 × ^{10-12 GeV-1} 的耦合，而来自未来巡天（如 CMB-S4）的观测可以将这一范围扩大近一个数量级。