论文标题
大规模结构重建具有短波长模式
Large Scale Structure Reconstruction with Short-Wavelength Modes
论文作者
论文摘要
大规模密度模式很难测量，因为它们对银河系调查中的系统观察误差敏感，但是我们可以通过观察它们对小规模扰动的影响来间接研究它们。宇宙学扰动理论预测，二阶密度不均匀性是短波和长波长模式的卷积。这是因为小规模的结构以不同的速度生长，具体取决于它们居住的大规模环境。这在傅立叶空间的两点统计中引起了一个非正式项，我们将其用作大规模场的二次估计器的基础。我们证明，该二次估计量在大小（2.5 H^{ - 1} GPC）^3的N体模拟中效果很好。特别是，二次估计量仅使用小规模信息成功地重建了长波长模式。这为研究最大的可观察量表研究结构打开了新的机会。
Large scale density modes are difficult to measure because they are sensitive to systematic observational errors in galaxy surveys, but we can study them indirectly by observing their impact on small scale perturbations. Cosmological perturbation theory predicts that second-order density inhomogeneities are a convolution of a short- and a long-wavelength mode. This arises physically because small scale structures grow at different rates depending on the large scale environment in which they reside. This induces an off-diagonal term in the two-point statistics in Fourier space that we use as the basis for a quadratic estimator for the large scale field. We demonstrate that this quadratic estimator works well on an N-body simulation of size (2.5 h^{-1} Gpc)^3. In particular, the quadratic estimator successfully reconstructs the long-wavelength modes using only small-scale information. This opens up novel opportunities to study structure on the largest observable scales.
