HIGH ENERGY THEORY / RELATIVITY / COSMOLOGY SEMINARS
Fall 2006
Friday September 22 Seminar :
Sergei Winitzki (Ludwig-Maximilians University, Munich)
Title : Quantum cosmology and the conditions at birth of the universe
Abstract:
| Cosmology ultimately aims to
explain the initial conditions at the beginning of time
and the entire subsequent evolution of the universe. The
"beginning of time" can be understood in the
Wheeler-DeWitt approach to quantum gravity, where
homogeneous universes are described by a Schroedinger
equation with a potential barrier. Quantum tunneling
through the barrier is interpreted as a spontaneous
creation of a small (Planck-size) closed universe, which
then enters the regime of cosmological inflation and
reaches an extremely large size. After sufficient growth,
the universe can be adequately described as a classical
spacetime with quantum matter. The initial quantum state
of matter in the created universe can be determined by
solving the Schroedinger equation with appropriate
boundary conditions. I show that the most likely initial
state is close to the vacuum state. This is the initial
condition for inflation favored both by observational
data and theoretical considerations. |
Host : Armendariz-Picon