Linearisation with Cosmological Perturbation Theory

Abstract

We propose a new method to linearise cosmological mass density fields using higher order Lagrangian perturbation theory (LPT). We demonstrate that a given density field can be expressed as the sum of a linear and a nonlinear component which are tightly coupled to each other by the tidal field tensor within the LPT framework. The linear component corresponds to the initial density field in Eulerian coordinates, and its mean relation with the total field can be approximated by a logarithm (giving theoretical support to recent attempts to find such component). We also propose to use a combination of the linearisation method and the continuity equation to find the mapping between Eulerian and Lagrangian coordinates. In addition, we note that this method opens the possibility of use directly higher order LPT on nonlinear fields. We test our linearization scheme by applying it to the z~0.5 density field from an N-body simulation. We find that the linearised version of the full density field can be successfully recovered on >~5 h^{-1}Mpc, reducing the skewness and kurtosis of the distribution by about one and two orders of magnitude, respectively. This component can also be successfully traced back in time, converging towards the initial unevolved density field at z~100. We anticipate a number of applications of our results, from predicting velocity fields to estimates of the initial conditions of the universe, passing by improved constraints on cosmological parameters derived from galaxy clustering via reconstruction methods.

14 pages, 8 figures

References in corpus (11)

• Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak
• The detectability of baryonic acoustic oscillations in future galaxy surveys
• Cosmological baryonic and matter densities from 600,000 SDSS Luminous Red Galaxies with photometric redshifts
• Galaxy Bias and its Effects on the Baryon Acoustic Oscillations Measurements
• Rejuvenating Power Spectra II: the Gaussianized galaxy density field
• Power spectrum of the SDSS luminous red galaxies: constraints on cosmological parameters
• Estimating cosmic velocity fields from density fields and tidal tensors
• Observational biases in Lagrangian reconstructions of cosmic velocity fields
• Increasing the Fisher Information Content in the Matter Power Spectrum by Non-linear Wavelet Weiner Filtering
• Straightening the Density-Displacement Relation with a Logarithmic Transform
• Gaussianizing the non-Gaussian lensing convergence field II: the applicability to noisy data

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