论文标题
ET对各向异性随机引力波背景的敏感性
ET sensitivity to the anisotropic Stochastic Gravitational Wave Background
论文作者
论文摘要
我们研究了一对爱因斯坦望远镜（ET）（假设位于当前正在考虑的ET的两个地点）对随机引力波背景（SGWB）的各向异性的敏感性。我们专注于$ \ ell = 0,2,4 $在球形谐波中扩展SGWB的多物，因为这对探测器在观察到的频率和两个站点之间的距离之间的产物之间运行的事实被抑制了对其他多物的敏感性。在此制度中，各向异性信号的干涉仪重叠函数可获得非常简单的分析表达式。这些表达式也可以应用于在此制度中运行的其他任何对两个干涉仪（其两个臂之间任意开口角的）。一旦两个位点的顶点的测量值最佳地组合在一起，对SGWB的多物的敏感性仅取决于两个位点的纬度，其经度的差异不取决于它们的手臂的方向。
We study the sensitivity of a pair of Einstein Telescopes (ET) (hypothetically located at the two sites currently under consideration for ET) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We focus on the $\ell =0,2,4$ multipoles of an expansion of the SGWB in spherical harmonics, since the sensitivity to other multipoles is suppressed due to the fact that this pair of detector operates in a regime for which the product between the observed frequency and the distance between the two sites is much smaller than one. In this regime, the interferometer overlap functions for the anisotropic signal acquire very simple analytic expressions. These expressions can also be applied to any other pairs of interferometers (each one of arbitrary opening angle between its two arms) operating in this regime. Once the measurements at the vertices of the two sites are optimally combined, the sensitivity to the multipoles of the SGWB depends only on the latitude of the two sites, on the difference of their longitude, but not on the orientation of their arms.
