论文标题
重建巴属声学振荡的最佳运输重建
Optimal Transport Reconstruction of Baryon Acoustic Oscillations
论文作者
论文摘要
提出了一种加权，半混凝土，快速最佳运输（OT）算法，用于从其进化的欧拉（Eulerian）位置重建原始halos的拉格朗日位置。该算法利用了对偏置示踪剂的质量估计和剩余质量的分布（“灰尘”）的分布，但对质量估计中的错误是强大的。使用最先进的宇宙学模拟的测试表明，如果假定灰尘具有均匀的空间分布，那么示踪剂的OT重建对配对相关函数的形状非常接近线性理论，从而在BAO距离尺度上实现了较弱的BAO距离量表中的次级次级精确度，该理论依赖于弱的，即使在整个过程中，也可以依靠。 OT凭借更复杂的模型，返回了位移场的估计值，该估计会产生原始途径位置的精美重建，从而产生示踪剂的初始对相关函数的形状和振幅。这可以直接和独立地确定偏见因子$ b $和涂抹量表$σ$，这可能提供了破坏$ b $和$σ_8$之间的新方法。
A weighted, semi-discrete, fast optimal transport (OT) algorithm for reconstructing the Lagrangian positions of proto-halos from their evolved Eulerian positions is presented. The algorithm makes use of a mass estimate of the biased tracers and of the distribution of the remaining mass (the `dust'), but is robust to errors in the mass estimates. Tests with state-of-art cosmological simulations show that if the dust is assumed to have a uniform spatial distribution, then the shape of the OT-reconstructed pair correlation function of the tracers is very close to linear theory, enabling sub-percent precision in the BAO distance scale that depends weakly, if at all, on a cosmological model. With a more sophisticated model for the dust, OT returns an estimate of the displacement field which yields superb reconstruction of the proto-halo positions, and hence of the shape and amplitude of the initial pair correlation function of the tracers. This enables direct and independent determinations of the bias factor $b$ and the smearing scale $Σ$, potentially providing new methods for breaking the degeneracy between $b$ and $σ_8$.
