论文标题
在随机重力波背景中对各向异性的预测PULSAR时序阵列敏感性
Forecasting pulsar timing array sensitivity to anisotropy in the stochastic gravitational wave background
论文作者
论文摘要
在不久的将来，PULSAR时正时阵列（PTA）检测到纳米赫兹 - 频率引力波背景（GWB）的统计各向异性。通过开发一个固定地限制GWB功率为正的频繁统计框架，我们建立了依赖多极依赖的各向异性决策阈值的缩放关系，这些决策阈值是PTA中噪声特性，计时基准和脉冲组的函数的函数。我们验证了$（i）$多数的脉冲星和$（ii）$因素，导致脉冲星之间互相关测量的不确定性降低，导致总体GWB信噪比较高，并且各向异性决策阈值较低，从而拒绝同位素副本的零假设。使用对现实的纳米格拉夫数据集的保守模拟，我们预计具有角力$ c_ {l = 1}> 0.3 \，c_ {l = 0} $的各向异性GWB可能足以在$ p = 3 \ times10^\ 3} $ sim3 $ sim3 $ seles a n y a y y y y附近，在$ p = 3} $ 20 $ 20 $ p = 3} $ 20 $ ploped y yous-plopy张力上可能会产生张力。基线。我们提出了可以使用的缩放关系，可以将这些阈值映射到任何数量的脉冲星，脉冲星噪声属性和天空覆盖范围。我们讨论了PTA如何改善各向异性的检测前景，以及如何对我们的方法进行调整以进行更广泛的搜索。
Statistical anisotropy in the nanohertz-frequency gravitational-wave background (GWB) is expected to be detected by pulsar timing arrays (PTAs) in the near future. By developing a frequentist statistical framework that intrinsically restricts the GWB power to be positive, we establish scaling relations for multipole-dependent anisotropy decision thresholds that are a function of the noise properties, timing baselines, and cadences of the pulsars in a PTA. We verify that $(i)$ a larger number of pulsars, and $(ii)$ factors that lead to lower uncertainty on the cross-correlation measurements between pulsars, lead to a higher overall GWB signal-to-noise ratio, and lower anisotropy decision thresholds with which to reject the null hypothesis of isotropy. Using conservative simulations of realistic NANOGrav datasets, we predict that an anisotropic GWB with angular power $C_{l=1} > 0.3\,C_{l=0}$ may be sufficient to produce tension with isotropy at the $p = 3\times10^{-3}$ ($\sim3σ$) level in near-future NANOGrav data with a $20$~yr baseline. We present ready-to-use scaling relationships that can map these thresholds to any number of pulsars, configuration of pulsar noise properties, and sky coverage. We discuss how PTAs can improve the detection prospects for anisotropy, as well as how our methods can be adapted for more versatile searches.
