Wavelet analysis of the formation of the cosmic web

TL;DR

This paper uses wavelet analysis on numerical simulations to study the stability and formation of the cosmic web's structure, revealing that large-scale density features are stable over time and present early in the universe's evolution.

Contribution

It introduces wavelet analysis to track the evolution of density perturbations in the cosmic web, highlighting the early presence and stability of large-scale structures.

Findings

Positions of density maxima and minima are stable over time.

Larger wavelength perturbations have more stable extrema.

The cosmic web skeleton was present early in the universe.

Abstract

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. Using numerical simulations we study the evolution of phases of density perturbations of different scales to understand the formation and evolution of the cosmic web. We apply the wavelet analysis to follow the evolution of high-density regions (clusters and superclusters) of the cosmic web. We show that the positions of maxima and minima of density waves (their spatial phases) almost do not change during the evolution of the structure. Positions of extrema of density perturbations are the more stable, the larger is the wavelength of perturbations. Combining observational and simulation data we conclude that the skeleton of the cosmic web was present already in an early stage of structure evolution.