TESTING COSMOGONIC MODELS WITH GRAVITATIONAL LENSING

Gravitational lensing provides a strict test of cosmogonic models beca use it is directly sensitive to mass inhomogeneities. Detailed numeric al propagation of light rays through a universe that has a distributio n of inhomogeneities derived from the standard CDM (cold dark matter) scenario, with the aid of massive, fully nonlinear computer simulation s, was used to test the model. It predicts that more widely split quas ar images should have been seen than were actually found. These and ot her inconsistencies rule out the Cosmic Background Explorer (COBE)-nor malized CDM model with density parameter Omega = 1 and the Hubble cons tant (H-0) = 50 kilometers second(-1) megaparsec(-1); but variants of this model might be constructed, which could pass the stringent tests provided by strong gravitational tensing.