Parametric Resonance of Entropy Perturbations in Massless Preheating

Abstract

Here, we revisit the question of possible preheating of entropy modes in a two field model with a massless inflaton coupled to a matter scalar field. Using a perturbative approximation to the covariant method we demonstrate that there is indeed a parametric instability of the entropy mode which then at second order leads to exponential growth of the curvature fluctuation on super-Hubble scale. Back-reaction effects shut off the induced curvature fluctuations, but possibly not early enough to prevent phenomenological problems. This confirms previous results obtained using different methods and resolves a controversy in the literature.

13 pages, 1 figure, accepted by IJMPD

References in corpus (5)

• Nonperturbative Dynamics Of Reheating After Inflation: A Review
• Inflation and the Scale Dependent Spectral Index: Prospects and Strategies
• Non-Gaussian Spikes from Chaotic Billiards in Inflation Preheating
• DEFROST: A New Code for Simulating Preheating after Inflation
• Generating the primordial curvature perturbations in preheating

Cited by in corpus (1)

• Numerical study of inflationary preheating with arbitrary power-law potential and a realization of curvaton mechanism