Get access

Evolution of cosmological perturbations in Bose–Einstein condensate dark matter


  • T. Harko

    Corresponding author
    1. Department of Physics and Center for Theoretical and Computational Physics, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, Hong Kong SAR, China
    Search for more papers by this author



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.

Get access to the full text of this article