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arXiv · 1105.3982

Preheating with the Brakes On: The Effects of a Speed Limit

Johanna Karouby·Bret Underwood·Aaron C. Vincent
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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.

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Johanna Karouby, Bret Underwood, Aaron C. Vincent. 2011-08-26. Preheating with the Brakes On: The Effects of a Speed Limit. https://doi.org/10.1103/physrevd.84.043528

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