Evolution of cosmological perturbations in Bose-Einstein condensate dark matter

TL;DR

This paper investigates how Bose-Einstein condensate dark matter influences the evolution of the universe and structure formation, revealing significant differences from traditional pressureless dark matter models through analytical and numerical analysis.

Contribution

It introduces a new cosmological model based on Bose-Einstein condensate dark matter and analyzes its impact on cosmic evolution and perturbations using both analytical and numerical methods.

Findings

Significant differences in cosmological evolution compared to pressureless dark matter.

Modified large scale structure formation due to condensate dark matter.

Analytical and numerical solutions for perturbation evolution.

Abstract

We consider the global cosmological evolution and the evolution of the density contrast in the Bose-Einstein condensate dark matter model, in the framework of a Post-Newtonian cosmological approach. In the Bose-Einstein model, dark matter can be described as a non-relativistic, Newtonian gravitational condensate, whose density and pressure are related by a barotropic equation of state. For a condensate with quartic non-linearity, the equation of state is polytropic with index $n=1$. The basic equation describing the evolution of the perturbations of the Bose-Einstein condensate is obtained, and its solution is studied by using both analytical and numerical methods. The global cosmological evolution as well as the evolution of the perturbations of the condensate dark matter shows significant differences with respect to the pressureless dark matter model, considered in the framework of standard cosmology. Therefore the presence of condensate dark matter could have modified drastically the cosmological evolution of the early universe, as well as the large scale structure formation process.