Open AccessInformation content of the non‐linear matter power spectrum
Author(s) -
Rimes Christopher D.,
Hamilton Andrew J. S.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2005.00051.x
Subject(s) - matter power spectrum , spectral density , wavenumber , formalism (music) , physics , nonlinear system , amplitude , statistical physics , mathematics , statistics , optics , quantum mechanics , cosmology , art , musical , dark energy , visual arts
We use an ensemble of N ‐body simulations of the currently favoured (concordance) cosmological model to measure the amount of information contained in the non‐linear matter power spectrum about the amplitude of the initial power spectrum. Two surprising results emerge from this study: (i) that there is very little independent information in the power spectrum in the translinear regime ( k ≃ 0.2 –0.8 h Mpc −1 at the present day) over and above the information at linear scales; and (ii) that the cumulative information begins to rise sharply again with increasing wavenumber in the non‐linear regime. In the fully non‐linear regime, the simulations are consistent with no loss of information during translinear and non‐linear evolution. If this is indeed the case then the results suggest a picture in which translinear collapse is very rapid, and is followed by a bounce prior to virialization, impelling a wholesale revision of the HKLM–Peacock & Dodds formalism.