1. The Equation of State After Preheating A talk that should have been given by Dmitry Podolsky, or possibly Jean- Francois Dufaux hep-ph/0507096 D. Podolsky, G. Felder, L. Kofman, and M. Peloso

2. Outline Overview Overview What happens in the simplest model What happens in the simplest model What to do about it What to do about it Some implications Some implications Conclusions Conclusions

3. Overview Consider the model Consider the model When the energy is dominated by the homogeneous inflaton field (after inflation) the equation of state is matter domination. When the energy is dominated by the homogeneous inflaton field (after inflation) the equation of state is matter domination. When the energy is dominated by the conformal, quartic term the equation of state is radiation domination. When the energy is dominated by the conformal, quartic term the equation of state is radiation domination.

4. The Simplest Model

5. Preheating With a Cubic Term

6. Modulated Fluctuations

7. Conclusions Any realistic model of reheating must ensure that the universe acquires a radiation dominated equation of state. Any realistic model of reheating must ensure that the universe acquires a radiation dominated equation of state. Preheating moves you most of the way very rapidly, but after that the process occurs very slowly. Preheating moves you most of the way very rapidly, but after that the process occurs very slowly. The timing depends on the coupling and may lead to modulated fluctuations. The timing depends on the coupling and may lead to modulated fluctuations.