Rolling in the Modulated Reheating Scenario

Abstract

In the modulated reheating scenario, the field that drives inflation has a spatially varying decay rate, and the resulting inhomogeneous reheating process generates adiabatic perturbations. We examine the statistical properties of the density perturbations generated in this scenario. Unlike earlier analyses, we include the dynamics of the field that determines the inflaton decay rate. We show that the dynamics of this modulus field can significantly alter the amplitude of the power spectrum and the bispectrum, even if the modulus field has a simple potential and its effective mass is smaller than the Hubble rate. In some cases, the evolution of the modulus amplifies the non-Gaussianity of the perturbations to levels that are excluded by recent observations of the cosmic microwave background. Therefore, a proper treatment of the modulus dynamics is required to accurately calculate the statistical properties of the perturbations generated by modulated reheating.

27 pages, 11 figures: minor changes made to match version in JCAP

References in corpus (5)

• Non-Gaussianity in the modulated reheating scenario
• Primordial Curvature Fluctuation and Its Non-Gaussianity in Models with Modulated Reheating
• Probing String Theory with Modulated Cosmological Fluctuations
• Curvature and isocurvature perturbations from two-field inflation in a slow-roll expansion
• What Planck does not tell us about inflation

Cited by in corpus (5)

• Nonperturbative Dynamics Of Reheating After Inflation: A Review
• The next non-Gaussianity frontier: what can a measurement with $\sigma (f_{\mathrm{NL}})\lesssim 1$ tell us about multifield inflation?
• Non-Gaussianity in multi-sound-speed disformally coupled inflation
• Constraints on variations in inflaton decay rate from modulated preheating
• Escape from the swamp with spectator