论文标题
闯入者大声说出来：使用小尺度镜头各向异性研究黑暗宇宙
Interlopers speak out: studying the dark universe using small-scale lensing anisotropies
论文作者
论文摘要
强烈的镜头系统是对暗物质在小尺度上分布的强大探针。在本文中，我们表明源和观察者之间的视线光环在有效镜头偏转场的两点函数中产生了独特的各向异性签名。我们特别表明，在视线光环和主镜头平面之间的非线性耦合在这个两点函数上刻有特征性四极矩的特征四极力矩，该函数的幅度反映了强烈镜片范围内的这种光环。我们讨论如何通过将不同的多极矩的比率占据比率，在质量表变换下可以使这种可观察物变得可靠。我们还证明，由于理想条件下这种独特的各向异性签名，未来极大的望远镜具有检测四极力矩的能力。我们的方法打开了统计上的大门，将视线光环与主镜头子结构对镜片图像的影响区分开，因此可以以新的方式探测暗物质物理。
Strongly lensed systems are powerful probes of the distribution of dark matter on small scales. In this paper, we show that line-of-sight haloes between the source and the observers give rise to a distinct anisotropic signature in the two-point function of the effective lensing deflection field. We show in particular that the non-linear coupling between line-of-sight haloes and the main-lens plane imprints a characteristic quadrupole moment on this two-point function whose amplitude reflects the abundance of such haloes within the strongly lensed field. We discuss how, by taking ratios of different multipole moments, such observables could be made robust under the mass-sheet transform. We also demonstrate that future extremely large telescopes have the ability to detect the quadrupole moment due to this unique anisotropic signature under ideal conditions. Our approach opens the door to statistically distinguish the effect of line-of-sight haloes from that of the main-lens substructure on lensed images, hence allowing one to probe dark matter physics in a new way.
