Chemical inhomogeneity of the post-reionization universe

The statistical properties of the spatial distribution of metals in the intergalactic medium are analyzed during the initial stages of its enrichment, when mixing is determined by the Kelvin-Helmholtz and Rayleigh-Taylor instabilities. The saturation of instabilities due to the damping of relative motions of gaseous flows leads to an incomplete mixing, hence on the small scale there appear regions with high (i.e., close to the initial) metallicity. A comparison with observational data shows that in the "post-reionization" Universe (z < 5) the irregularity of the metal distribution exhibits the features, characteristic of mixing with saturation of hydrodynamic instabilities.