The growth of linear perturbations in generic defect models for structure formation

We study the growth of linear perturbations induced by a generic causal scaling source as a function of the cosmological parameters h, Omega(0)(m) and Omega(0)(Lambda). We show that for wavenumbers k greater than or similar to 0.01 h Mpc(-1) the spectrum of density and velocity perturbations scales in a similar way to that found in inflationary models with primordial perturbations. We show that this result is independent of the more-or-less incoherent nature of the source, the small-scale power spectrum of the source and of deviations from scaling that naturally occur at late times if Omega(0)(m) not equal 1.