|Speaker:||Alexander Vikman (CERN)|
|Title:||Cosmology, Scalar Fields and Hydrodynamics|
|Date (JST):||Fri, Jun 03, 2011, 13:30 - 15:00|
|Place:||Seminar Room A|
The history of our universe contains at least two periods of accelerated expansion.
The first, primordial acceleration, is usually called "Inflation" and is responsible for the tremendous size of our universe, it's spatial flatness, and for the production of large scale structures. The second is the recent cosmological acceleration, driven by either an unnaturally small cosmological constant or by an unknown "Dark Energy". Scalar fields are extensively used to model cosmological dynamics during both these époques. However, it turns out that the main observational results can be written in terms of hydrodynamical quantities like pressure, energy density, and the speed of sound. I will review some of the results of scalar field cosmology and discuss the relation between scalar fields and hydrodynamics. In particular, I will discuss novel models with unconventional scalar fields that correspond to imperfect fluids.