Emergence of a classical Universe from quantum gravity and cosmology.
I describe how we can understand the classical appearance of our world from a universal quantum theory. The essential ingredient is the process of decoherence. I start with a general discussion in ordinary quantum theory and then turn to quantum gravity and quantum cosmology. There is a whole hierarchy of classicality from the global gravitational field to the fluctuations in the cosmic microwave background, which serve as the seeds for the structure in the Universe.
Institute for Theoretical Physics, University of Cologne, Zülpicher Strasse 77, 50937 Köln, Germany. kiefer@thp.uni-koeln.de
Claus
C
Kiefer