Large Scale Density Inhomogeneities in the Universe

Abstract

Sachs and Wolfe have recently considered the possibility of large scale density inhomogeneities in the universe with characteristic dimensions of the order of 109 parsecs.1. The suggestion2 that quasi-stellar sources with highly red-shifted spectra are not isotropically distributed has aroused interest in large inhomogeneities. Rees and Sciama3 have suggested that the tendency to cluster of quasi-stellar sources with large z implies that the mass of the universe may not be homogeneously distributed on a scale of z ∼ 1. Although the observational status of the anisotropy of the distribution of these sources is in some doubt4, we have recently obtained results which appear to set rather stringent limits on the magnitude of possible density inhomogeneities in the universe.