Preheating with the Brakes On: The Effects of a Speed Limit
Abstract
We study preheating in models where the inflaton has a non-canonical kinetic term, containing powers of the usual kinetic energy. The inflaton field oscillating about its potential minimum acts as a driving force for particle production through parametric resonance. Non-canonical kinetic terms can impose a speed limit on the motion of the inflaton, modifying the oscillating inflaton profile. This has two important effects: it turns a smooth sinusoidal profile into a sharp saw-tooth, enhancing resonance, and it lengthens the period of oscillations, suppressing resonance. We show that the second effect dominates over the first, so that preheating with a non-canonical inflaton field is less efficient than with canonical kinetic terms, and that the expansion of the Universe suppresses resonance even further.
Cite
@article{arxiv.1105.3982,
title = {Preheating with the Brakes On: The Effects of a Speed Limit},
author = {Johanna Karouby and Bret Underwood and Aaron C. Vincent},
journal= {arXiv preprint arXiv:1105.3982},
year = {2011}
}
Comments
12 pages, 6 figures