A new fully non-linear reconstruction algorithm for the accurate recovery of the Bary- onic Acoustic Oscillations (BAO) scale in two-point correlation functions is proposed, based on the least-action principle and extending the Fast Action Minimisation method by Nusser & Branchini (2000). Especially designed for massive spectroscopic surveys, it is tested on dark-matter halo catalogues extracted from the deus-fur ΛCDM simula- tion to trace the trajectories of up to ∼ 207, 000 haloes backward-in-time, well beyond the first-order Lagrangian approximation. The new algorithm successfully recovers the BAO feature in real and redshift-space in both the monopole and the anisotropic two-point correlation function, also for anomalous samples showing misplaced or ab- sent signature of BAO. In redshift space, the non-linear displacement parameter ΣNL is reduced from 11.8±0.3h−1Mpc at redshift z = 0 to 4.0±0.5h−1Mpc at z ≃ 37 after recon- struction. A comparison with the first-order Lagrangian reconstruction is presented, showing that this techniques outperforms the linear approximation in recovering an unbiased measurement of the acoustic scale.
BAO reconstruction: A swift numerical action method for massive spectroscopic surveys
SARPA, ELENA;Matarrese, S.
2019
Abstract
A new fully non-linear reconstruction algorithm for the accurate recovery of the Bary- onic Acoustic Oscillations (BAO) scale in two-point correlation functions is proposed, based on the least-action principle and extending the Fast Action Minimisation method by Nusser & Branchini (2000). Especially designed for massive spectroscopic surveys, it is tested on dark-matter halo catalogues extracted from the deus-fur ΛCDM simula- tion to trace the trajectories of up to ∼ 207, 000 haloes backward-in-time, well beyond the first-order Lagrangian approximation. The new algorithm successfully recovers the BAO feature in real and redshift-space in both the monopole and the anisotropic two-point correlation function, also for anomalous samples showing misplaced or ab- sent signature of BAO. In redshift space, the non-linear displacement parameter ΣNL is reduced from 11.8±0.3h−1Mpc at redshift z = 0 to 4.0±0.5h−1Mpc at z ≃ 37 after recon- struction. A comparison with the first-order Lagrangian reconstruction is presented, showing that this techniques outperforms the linear approximation in recovering an unbiased measurement of the acoustic scale.Pubblicazioni consigliate
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