论文标题
在现场层面的红移空间中建模星系
Modeling Galaxies in Redshift Space at the Field Level
论文作者
论文摘要
我们开发了一个基于扰动理论的分析前向模型，以预测在实现初始条件的情况下，在田间水平上的红移空间过度密度。我们发现模型和模拟星系密度之间的残余噪声具有大尺度上的白色功率谱，大小可与射击噪声相当。在轻度的非线性方案中，我们看到$ K^2μ^2 $校正对噪声功率谱，对应于沿视线和较小尺度的较大噪声。此校正的参数形式以前是在理论上预测的，我们的模拟提供了对其存在的重要确认。我们还对现场级别的星系速度进行了建模，并将其与模拟的星系速度进行了比较，发现我们模拟星系样品的RMS速度残留物的一半是一半的rms速度残差。
We develop an analytical forward model based on perturbation theory to predict the redshift-space galaxy overdensity at the field level given a realization of the initial conditions. We find that the residual noise between the model and simulated galaxy density has a power spectrum that is white on large scales, with size comparable to the shot noise. In the mildly nonlinear regime, we see a $k^2μ^2$ correction to the noise power spectrum, corresponding to larger noise along the line of sight and on smaller scales. The parametric form of this correction has been predicted on theoretical grounds before, and our simulations provide important confirmation of its presence. We have also modeled the galaxy velocity at the field-level and compared it against simulated galaxy velocities, finding that about $10\%$ of the galaxies are responsible for half of the rms velocity residual for our simulated galaxy sample.
