Testing Inflation with the Cosmic Background Radiation

In inflation cosmologies, cosmic structure develops through the gravitational instability of the inevitable quantum noise in primordial scalar fields. I show how the acceleration of the universe defines the shape of the primordial spectrum of gravitational metric and scalar field fluctuations. I assess how we can determine the shape and overall amplitude over the five decades or so of spatial wavelengths we can probe, and use current data … to show how far we are in this program. Broad-band power amplitudes are given for CMB anisotropy detections up to spring 1994 … I show that COBE band-powers found with full Bayesian analysis of the $53,90,31$ $a$+$b$ GHz first year DMR (and FIRS) maps are in good agreement, and are essentially independent of spectral slope and degree of (sharp) signal-to-noise filtering. Further, after (smooth) optimal signal-to-noise filtering (\ie Weiner-filtering), the different DMR maps reveal the same large scale features and correlation functions with little dependence upon slope. However, the most probable slope depends upon how the maps are filtered: with no filtering whatsoever, the slope is high, but the power is not described by a single-slope law; as filtering is increased, the index moves nearer to inflation predictions. in {\it Relativistic Cosmology}, ed. M. Sasaki, Academic Press (1994) Proc. 8th Nishinomiya-Yukawa Memorial Symposium, Japan, October 1993