SEMIEMPIRICAL SEEDED ISOCURVATURE COSMOGONIES

Main predictions of the baryon isocurvature model for structure format ion are reproduced if the primeval entropy per baryon is constant and homogeneity is broken by a clumpy distribution of seed masses. The con stant entropy per baryon may reconcile the cosmogony with the standard model for the origin of the light elements. The seeds could be long-l ived cosmic field structures or inhomogeneously produced nonbaryonic c old dark matter, if the needed primeval space distribution could be ar ranged. The constraints from the large-scale distributions of galaxies and the thermal cosmic background radiation require OMEGA approximate ly 0.1. In some cases the primeval seed rms mass constrast deltarho(c) /rho(c) exceeds unity on the scale of clusters of galaxies, meaning th e fluctuations cannot be Gaussian, which could permit cluster formatio n in a low-density universe.