Non-linearity and Non-Gaussianity through Phase Information
Abstract
In the standard picture of structure formation, initially random-phase fluctuations are amplified by non-linear gravitational instability to produce a final distribution of mass which is highly non-Gaussian and has highly coupled Fourier phases. Second-order statistics, such as the power spectrum, are blind to this kind of phase association. We discuss the information contained in the phases of cosmological density fluctuations and their possible use in statistical analysis tools. In particular, we show how the bispectrum measures a particular form of phase association called quadratic phase coupling, show how to visualise phase association using colour models. These techniques offer the prospect of more complete tests of initial non-Gaussianity than those available at present.
Cite
@article{arxiv.astro-ph/0010521,
title = {Non-linearity and Non-Gaussianity through Phase Information},
author = {Peter Coles and Lung-Yih Chiang},
journal= {arXiv preprint arXiv:astro-ph/0010521},
year = {2009}
}
Comments
7 pages, 1 figure (two parts). To appear in the proceedings of The MPA/ESO/MPE Joint Astronomy Conference "Mining the Sky" held in Garching, Germany, July 31 - August 4 2000. To be published in the Springer-Verlag series "ESO Astrophysics Symposia"