The Density of Matter in the Universe and the Epoch of Galaxy Formation

A possible way of determining a lower bound to the density of matter in the Universe is discussed in which theoretical results on the delayed growth of density perturbations in open universes are compared with the observed counts of radio sources and quasars. The latter imply the intense formation of objects at a redshift z 2-4. The proposed model of the condensation and formation of sources satisfies the results of the source counts and explains the absence of absorption corresponding to the Ly-cc line in the spectra of quasars having z> 2.3. Key words: Density perturbation growth in open Universe - source counts - intergalactic gas