Evolution of density perturbations in a realistic universe

TL;DR

This paper provides a general solution for the evolution of density perturbations in a universe dominated by dark energy and dark matter, showing slow growth during radiation and significant amplification during matter and dark energy epochs.

Contribution

It derives a comprehensive solution for density perturbation evolution in a realistic universe considering recent cosmological parameter measurements.

Findings

Density perturbations grow slowly during radiation era.

Amplitude increases by about 4000 times in matter and dark energy epochs.

Supports the standard CDM model with extended solutions.

Abstract

Prompted by the recent more precise determination of the basic cosmological parameters and growing evidence that the matter-energy content of the universe is now dominated by dark energy and dark matter we present the general solution of the equation that describes the evolution of density perturbations in the linear approximation. It turns out that as in the standard CDM model the density perturbations grow very slowly during the radiation dominated epoch and their amplitude increases by a factor of about 4000 in the matter and later dark energy dominated epoch of expansion of the universe.