Stochastic contribution to the growth factor in the LCDM model

TL;DR

This paper investigates how stochastic noise influences the growth factor of density perturbations in the LCDM cosmological model, revealing that even small noise levels can cause significant deviations at late times.

Contribution

It introduces a stochastic component into the growth factor evolution and quantifies the noise level at which it impacts cosmological observations.

Findings

Noise significantly affects growth factor at late times for alpha>0.001

Stochastic effects can alter large-scale structure predictions

Quantitative estimates of noise impact levels

Abstract

We study the effect of noise on the evolution of the growth factor of density perturbations in the context of the LCDM model. Stochasticity is introduced as a Wiener process amplified by an intensity parameter alpha. By comparing the evolution of deterministic and stochastic cases for different values of alpha we estimate the intensity level necessary to make noise relevant for cosmological tests based on large-scale structure data. Our results indicate that the presence of random forces underlying the fluid description can lead to significant deviations from the nonstochastic solution at late times for alpha>0.001.