Iterative Reconstruction Excursions for Baryon Acoustic Oscillations and Beyond


The density field reconstruction technique has been widely used for reco v ering the baryon acoustic oscillation (BAO) feature in galaxy surv e ys that has been degraded due to non-linearities. Recent studies advocated adopting iterative steps to impro v e the reco v ery much be yond that of the standard technique. In this paper, we investigate the performance of a few selected iterative re- construction techniques focusing on the BAO and the broad-band shape of the two-point clustering. We include redshift-space dis- tortions, halo bias, and shot noise and inspect the components of the reconstructed field in Fourier space and in configuration space using both density field-based reconstruction and displacement field-based reconstruction. We find that the displacement field reconstruction becomes quickly challenging in the presence of non-negligible shot noise and therefore present surrogate methods that can be practically applied to a much more sparse field such as galaxies. For a galaxy field, implementing a debiasing step to remo v e the Lagrangian bias appears crucial for the displacement field reconstruction. We show that the iterative reconstruction does not substantially impro v e the BAO feature beyond an aggressively optimized standard reconstruction with a small smoothing kernel. Ho we ver, we find taking iterative steps allows us to use a small smoothing kernel more 'stably', i.e. without causing a substantial deviation from the linear power spectrum on large scales. In one specific example we studied, we find that a deviation of 13 per cent in P ( k ∼0 . 1 h Mpc-1 ) with an aggressive standard reconstruction can reduce to 3-4 per cent with iterative steps.



Keywords and Phrases

Cosmological Parameters; Large-Scale Structure of Universe

International Standard Serial Number (ISSN)

1365-2966; 0035-8711

Document Type

Article - Journal

Document Version


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© 2022 Royal Astronomical Society, All rights reserved.

Publication Date

01 Apr 2022