INFLATION AFTER COBE Lectures on Inflationary Cosmology∗

In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge—a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for—and the fundamentals of—inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the “initial data” for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models. 1 Hot Big Bang: Successes and Challenges