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.

12 pages, 6 figures

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• Nonperturbative Dynamics Of Reheating After Inflation: A Review
• Preheating after Multifield Inflation with Nonminimal Couplings, I: Covariant Formalism and Attractor Behavior
• Refining inflation using non-canonical scalars
• Preheating after multifield inflation with nonminimal couplings, II: Resonance Structure
• K-Oscillons: Oscillons with Non-Canonical Kinetic Terms
• Preheating with Non-Minimal Kinetic Terms
• A Theory of Self-Resonance After Inflation, Part 1: Adiabatic and Isocurvature Goldstone Modes
• A Theory of Self-Resonance After Inflation, Part 2: Quantum Mechanics and Particle-Antiparticle Asymmetry
• Oscillons during Dirac-Born-Infeld Preheating
• Preheating in a DBI Inflation Model
• Enhanced tensor non-Gaussianities in presence of a source
• Non-Linear Resonance in Relativistic Preheating
• Frustration of resonant preheating by exotic kinetic terms
• (P)reheating Effects of the Kähler Moduli Inflation I Model
• Aspects of inflation and the very early universe