论文标题
随机重力波背景的脉冲星时正时阵列相关测量的脉冲星和宇宙方差
Pulsar and cosmic variances of pulsar timing-array correlation measurements of the stochastic gravitational wave background
论文作者
论文摘要
Pulsar时正时阵列相关测量为测试宇宙学新颖的纳米霍茨引力波状态的重力性质提供了一个令人兴奋的机会。随机引力背景是高斯和随机的，而天空中的脉冲星对有限。这给相关测量带来了理论上的不确定性，即由于脉冲星的采样和高斯信号引起的宇宙方差引起的脉冲方差。我们证明了依靠功率谱形式主义的均值和降低相关性的平均值和差异的直接计算。我们保持任意的脉冲星距离，并考虑超出爱因斯坦重力的重力波模式以及整个光锥，从而呈现最通用，最重要的是，对方差的数值有效计算。
Pulsar timing-array correlation measurements offer an exciting opportunity to test the nature of gravity in the cosmologically novel nanohertz gravitational wave regime. The stochastic gravitational wave background is assumed Gaussian and random, while there are limited pulsar pairs in the sky. This brings theoretical uncertainties to the correlation measurements, namely the pulsar variance due to pulsar samplings and the cosmic variance due to Gaussian signals. We demonstrate a straightforward calculation of the mean and the variances on the Hellings-Downs correlation relying on a power spectrum formalism. We keep arbitrary pulsar distances and consider gravitational wave modes beyond Einstein gravity as well as off the light cone throughout, thereby presenting the most general and, most importantly, numerically efficient calculation of the variances.
