The end of inflation and the approach to preheating

How does the universe reheat after inflation? We will discuss some recent work in which the possible role of inflaton fragmentation and the formation of fun non-topological objects such as oscillons could play an important role in pre heating the universe. We will also consider the possibility that on the way to reheating, the universe underwent a period of kination during which the energy density of the moduli field is dominated by its kinetic energy, followed by a tracking regime in which the field scaled like the background matter that is being produced. These features could arise in string cosmology and we will discuss some of their potential consequences.