Inflation: From Theory to Observation and Back

Abstract

Alan Guth introduced cosmologists to inflation at the 1980 Texas Symposium. Since, inflation has had almost as much impact on cosmology as the big-bang model itself. However, unlike the big-bang model, it has little observational support. Hopefully, that situation is about to change as a variety and abundance of data begin to test inflation in a significant way. The observations that are putting inflation to test involve the formation of structure in the Universe, especially measurements of the anisotropy of the cosmic background radiation. The cold dark matter models of structure formation motivated by inflation are holding up well as the observational tests become sharper. In the next decade inflation will be tested even more significantly, with more precise measurements of CBR anisotropy, the mean density of the Universe, the Hubble constant, and the distribution of matter, as well as sensitive searches for the nonbaryonic dark matter predicted to exist by inflation. As an optimist I believe that we may be well on our way to a standard cosmology that includes inflation and extends back to around 10^{-32} sec, providing an important window on the earliest moments and fundamental physics.