Wavelet analysis of the cosmic web formation

¹ Tartu Observatory, 61602 Tõravere, Estonia
e-mail: einasto@aai.ee
² Estonian Academy of Sciences, 10130 Tallinn, Estonia
³ ICRANet, Piazza della Repubblica 10, 65122 Pescara, Italy
⁴ Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
⁵ Landau Institute for Theoretical Physics, 119334 Moscow, Russia
⁶ Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, 113-0033 Tokyo, Japan

Received: 4 November 2010
Accepted: 5 May 2011

Abstract

Context. According to the modern cosmological paradigm, galaxies and galaxy systems form from tiny density perturbations generated during the very early phase of the evolution of the Universe.

Aims. Using numerical simulations, we study the evolution of the density perturbation phases of different scales to understand the formation and evolution of the cosmic web.

Methods. We apply the wavelet analysis to follow the evolution of high-density regions (clusters and superclusters) of the cosmic web.

Results. We show that the maxima and minima positions of density waves (their spatial phases) almost do not change during the evolution of the structure. Positions of density perturbation extrema of are more stable for large scale perturbations. In the context of the present study we call density waves of scale  ≥64 h^-1 Mpc large, waves of scale  ≃32 h^-1 Mpc medium, and waves of scale  ≃8 h^-1 Mpc small, within a factor of 2.

Conclusions. In the cosmic structure formation of the synchronisation (coupling) of density waves of different scales plays an important role.