Cosmic Strings as a Candidate for Dark Matter. Astrophysical Formulae

Extract

We consider homogeneous, isotropic universe with arbitrary curvature (k=0, ±1), filled with dust, radiation, ˄-term and a set of noninteracting strings (i.e. scaling as ρ_s ∼ R⁻², hence yielding string dominated universe). For such model we find analytic solution of the Friedman equation using Weierstrass functions. We realize that addition of (rather unrealistic component) stable domain walls (ρ_w ∼ R⁻¹) to the model, does not essentially complicate the calculations.