EXTRACTING PRIMORDIAL DENSITY-FLUCTUATIONS

The combination of detections of anisotropy in cosmic microwave backgr ound radiation and observations of the large-scale distribution of gal axies probes the primordial density fluctuations of the universe on sp atial scales varying by three orders of magnitude. These data are foun d to be inconsistent with the predictions of several popular cosmologi cal models. Agreement between the data and the cold + hot dark matter model, however, suggests that a significant fraction of the matter in the universe may consist of massive neutrinos.