DENSITY-FLUCTUATIONS ON SUPER-HUBBLE SCALES

According to causality, the existence of density perturbations on scal es larger than the present Hubble radius y = 2c/H-0 is crucial to disc riminate between inflation and non-inflation models of the origin of i nhomogeneity of the universe. Observations of the cosmic background ra diation anisotropies favor a super-Hubble suppression on scales lambda (max) in the range 0.5-3.0y. Many of non-inflation models are consiste nt with such a suppression. Inflation models are certainly not in conf lict with this suppression, however one important parameter, the durat ion of the epoch of inflation, may need to be fine tuned.