Testing large-scale structure measurements against Fisher matrix predictions. Issue 10 (14th October 2021)

• Record Type: Journal Article
• Authors: Foroozan, Setareh; Krolewski, Alex; Percival, Will J.
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2021:Issue 10(2021)
• Publication Date: 2021-10-14
• Subjects: baryon acoustic oscillations -- cosmological parameters from LSS -- redshift surveys; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2021/10/044
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: We compare Baryonic Acoustic Oscillation (BAO) and Redshift Space Distortion (RSD) measurements from recent galaxy surveys with their Fisher matrix based predictions. Measurements of the position of the BAO signal lead to constraints on the comoving angular diameter distance DM and the Hubble distance DH that agree well with their Fisher matrix based expectations. However, RSD-based measurements of the growth rate f σ8 do not agree with the predictions made before the surveys were undertaken, even when repeating those predictions using the actual survey parameters. We show that this is due to a combination of effects including degeneracies with the geometric parameters DM and DH, and optimistic assumptions about the scale to which the linear signal can be extracted. We show that measurements using current data and large-scale modelling techniques extract an equivalent amount of signal to that in the linear regime for k ≲ 0.08 h Mpc -1, remarkably independent of the sample properties and redshifts covered.