SELF-REPLICATION COSMOLOGY: DARK PARTICLES AS A POSSIBLE UNIFIED NATURE OF DARK ENERGY AND DARK MATTER

This paper considers a hypothesis unifying dark energy and dark matter into a single entity: both are treated as manifestations of one population of hypothetical self-replicating dark particles whose number is not conserved. The mechanism is identified with adiabatic matter creation, which makes the hypothesis quantitative rather than qualitative. The behaviour of the component is shown to be governed by the ratio of the creation rate to the expansion rate, Γ/3H: for Γ/3H ≪ 1 the component behaves as pressureless matter and clusters, while for Γ/3H → 1 it behaves as a cosmological constant. The main result is quantitative: for the one-parameter family of creation rates Γ = 3αH₀(H₀/H)ⁿ the effective matter density at high redshift equals (1 − α)2/m with m = n + 1, whereas the amplitude α is fixed entirely by the present acceleration. Simultaneously matching the observed q₀ ≈ −0.55 and Ω_m ≈ 0.315 confines the exponent to m ≈ 2, that is, to the single case in which the background solution is exactly degenerate with ΛCDM. It follows that a unification of the dark sector through particle creation is possible, but only within a narrow window, and that testing it must proceed through the growth of perturbations rather than through the expansion history. The previously proposed explanation of flat rotation curves by creation pressure is withdrawn as having the wrong sign.