论文标题
扩展快速动作最小化方法：应用于SDSS-DR12组合样品
Extended Fast Action Minimisation method: application to SDSS-DR12 Combined Sample
论文作者
论文摘要
我们介绍了扩展快速动作最小化方法（EFAM）在真实数据集（SDSS-DR12组合样品）中的第一个应用，以在真实空间中重建星系轨道，其两点相关函数（2PCF）在真实空间中，并增强BARYONASOCTIC OSCOSTOT振动（BAO）峰值。为此，我们介绍了EFAM的新实施，该实施是针对选择效果，调查足迹和星系偏见的。我们使用重建的BAO峰来测量角直径距离，d_a（z）r^{fid} _s/r_s和Hubble参数，H（z）r_s/r_s/r^{fid} _s，归一化为音范式的标准，以示例r^{fid r^{fid r^{ d_a（z = 0.38）r^{fid} _s/r_s = 1090 +/- 29（mpc）^{ - 1}和h（z = 0.38）r_s}/r_s}/r^{fid} _s = 83 +/- 3（km s^{ - 1} mpc^{ - 1} mpc^{-1}）使用400个公开可用的SDSS-DR12模拟目录进行的验证测试表明，EFAM在重建2PCF中表现良好，以降至25H^{ - 1} MPC $的分离，即进入非线性式制度。此外，由于包括调查的红移空间失真，EFAM成功地删除了各向异性，这使我们能够减少模型中的自由参数的数量，并适合BAO峰之外的后式后续重建2PCF孔的全形状。恢复真实空间2PCF，EFAM提高了拟合参数的估计值的精度。与无重建情况相比，EFAM降低了Alcock-Paczynski失真参数的不确定性约为40％，而在非线性阻尼量表上的不确定性约为70％。这些结果表明，可以将EFAM成功应用于现有的红移星系目录，并应将其视为基于Zel'Dovich近似值的流行方法的下一代调查替代的重建工具。
We present the first application of the extended Fast Action Minimization method (eFAM) to a real dataset, the SDSS-DR12 Combined Sample, to reconstruct galaxies orbits back-in-time, their two-point correlation function (2PCF) in real-space, and enhance the baryon acoustic oscillation (BAO) peak. For this purpose, we introduce a new implementation of eFAM that accounts for selection effects, survey footprint, and galaxy bias. We use the reconstructed BAO peak to measure the angular diameter distance, D_A(z)r^{fid}_s/r_s, and the Hubble parameter, H(z)r_s/r^{fid}_s, normalized to the sound horizon scale for a fiducial cosmology r^{fid}_s, at the mean redshift of the sample z=0.38, obtaining D_A(z=0.38)r^{fid}_s/r_s=1090 +/- 29 (Mpc)^{-1}, and H(z=0.38)r_s}/r^{fid}_s=83 +/- 3 (km s^{-1}Mpc^{-1}), in agreement with previous measurements on the same dataset. The validation tests, performed using 400 publicly available SDSS-DR12 mock catalogues, reveal that eFAM performs well in reconstructing the 2PCF down to separations of 25h^{-1}Mpc$, i.e. well into the non-linear regime. Besides, eFAM successfully removes the anisotropies due to redshift-space distortion at all redshifts including that of the survey, allowing us to decrease the number of free parameters in the model and fit the full-shape of the back-in-time reconstructed 2PCF well beyond the BAO peak. Recovering the real-space 2PCF, eFAM improves the precision on the estimates of the fitting parameters. When compared with the no-reconstruction case, eFAM reduces the uncertainty of the Alcock-Paczynski distortion parameters of about 40% and that on the non-linear damping scale of about 70%. These results show that eFAM can be successfully applied to existing redshift galaxy catalogues and should be considered as a reconstruction tool for next-generation surveys alternative to popular methods based on the Zel'dovich approximation.
