标题： 从普朗克和Bicep2/Keck数据限制宇宙双折射 显示英文标题

标题： Constraints on cosmological birefringence from Planck and Bicep2/Keck data

摘要： 宇宙微波背景（CMB）的偏振可用于限制宇宙双折射效应，即可能由标准模型之外的宇称破坏物理引起的CMB光子线性偏振的旋转。 这种效应会在温度和B模式偏振之间以及E模式和B模式偏振之间产生非零的CMB交叉关联；而在标准宇宙学模型中，这两种交叉关联均为零。 我们使用最近发布的2015年Planck似然函数，结合Bicep2/Keck/Planck (BKP)似然函数来限制双折射角度$\alpha$。 我们的发现与未检测到的结果一致，对于{\sc 普朗克}数据得出$\alpha = 0.0^{\circ} \pm 1.3^{\circ} \mbox{ (stat)} \pm 1^{\circ} \mbox{ (sys)} $，对于BKP数据得出$\alpha = 0.30^{\circ} \pm 0.27^{\circ} \mbox{ (stat)} \pm 1^{\circ} \mbox{(sys)} $。 最后，我们预测了当将Planck高$\ell$的BB、TB和EB频谱纳入分析时，对未来约束条件的预期改进。 显示英文摘要

摘要： The polarization of cosmic microwave background (CMB) can be used to constrain cosmological birefringence, the rotation of the linear polarization of CMB photons potentially induced by parity violating physics beyond the standard model. This effect produces non-null CMB cross correlations between temperature and B mode-polarization, and between E- and B-mode polarization. Both cross-correlations are otherwise null in the standard cosmological model. We use the recently released 2015 Planck likelihood in combination with the Bicep2/Keck/Planck (BKP) likelihood to constrain the birefringence angle $\alpha$. Our findings, that are compatible with no detection, read $\alpha = 0.0^{\circ} \pm 1.3^{\circ} \mbox{ (stat)} \pm 1^{\circ} \mbox{ (sys)} $ for {\sc Planck} data and $\alpha = 0.30^{\circ} \pm 0.27^{\circ} \mbox{ (stat)} \pm 1^{\circ} \mbox{(sys)} $ for BKP data. We finally forecast the expected improvements over present constraints when the Planck BB, TB and EB spectra at high $\ell$ will be included in the analysis.