论文标题
红移空间中的宇宙潮汐重建
Cosmic tidal reconstruction in redshift space
论文作者
论文摘要
大型和小规模密度扰动之间的重力耦合导致各向异性扭曲，导致局部小规模物质波动。这种局部各向异性变形可用于重建大规模的物质分布，称为潮汐重建。在本文中，我们将潮汐重建方法应用于红移空间中的模拟星系。我们发现红移空间变形导致各向异性重建结果。虽然重建的径向模式更嘈杂，这主要是由于小规模的速度分散剂，但横向模式仍以高保真度重建，与原始的大规模密度模式息息相关。重建场的偏置在大尺度上显示出一种简单的角度依赖性，可以通过类似于线性红移空间失真的形式描述。噪声功率谱几乎是各向同性的，并且在大尺度上无关。这使得重建的潮汐场成为宇宙方差取消和多迹线分析的理想示踪剂，并对未来的21 〜cm强度映射调查具有深远的影响。
The gravitational coupling between large- and small-scale density perturbations leads to anisotropic distortions to the local small-scale matter fluctuations. Such local anisotropic distortions can be used to reconstruct the large-scale matter distribution, known as tidal reconstruction. In this paper, we apply the tidal reconstruction methods to simulated galaxies in redshift space. We find that redshift-space distortions lead to anisotropic reconstruction results. While the reconstructed radial modes are more noisy mainly due to the small-scale velocity dispersion, the transverse modes are still reconstructed with high fidelity, well correlated with the original large-scale density modes. The bias of the reconstructed field at large scales shows a simple angular dependence which can be described by a form similar to the linear redshift-space distortion. The noise power spectrum is nearly isotropic and scale-independent on large scales. This makes the reconstructed tides field an ideal tracer for cosmic variance cancellation and multi-tracer analysis and has profound implications for future 21~cm intensity mapping surveys.
