Title: The 'Alarming' Phenomenon of Particle Creation in the Expanding Universe


The expansion of the universe converts 'virtual' particles in to real particles. The record of this quantum effect may be encoded in the structure of temperature fluctuations in the cosmic microwave background radiation, the primordial seeds of structure formation, and perhaps in the nature of dark matter. In the talk I will explain how something as small as quantum fluctuations can lead to something as large as a galaxy, and review observational tests of the idea.