Related papers: Super-horizon perturbations and preheating
This paper concludes our semi-analytic study of preheating in inflationary models comprised of multiple scalar fields coupled nonminimally to gravity. Using the covariant framework of paper I in this series, we extend the rigid-spacetime…
In single clock models of inflation the coupling between modes of very different scales does not have any significant dynamical effect during inflation. It leads to interesting projection effects. Larger and smaller modes change the…
How much does the curvature perturbation change after it leaves the horizon, and when should one evaluate the power spectrum? To answer these questions we study single field inflation models numerically, and compare the evolution of…
Curvature perturbations generated after the end of inflation are estimated for a generic multi-field inflationary potential. The curvature perturbations are generated by conversion of inflationary isocurvature perturbations, similar to…
We study the effect on the primordial cosmological perturbations of a sharp transition from inflationary to a radiation and matter dominated epoch respectively. We assume that the perturbations are generated by the vacuum fluctuations of a…
We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order…
Recently it has become clear that the resonant amplification of quantum field fluctuations at preheating must be accompanied by resonant amplification of scalar metric perturbations, since the two are united by Einstein's equations.…
We investigate the evolution of the non-linear long wavelength fluctuations during preheating after inflation. By using the separate universe approach, the temporal evolution of the power spectrum of the scalar fields and the curvature…
The epochs of reheating and preheating are studied in a simple extension of the Starobinsky inflationary model, which consists of an $R^2$--correction to the Einstein--Hilbert action and an additional scalar field. We find that if the…
We investigated the possibility that nonlinear gravitational effects influence the preheating era after inflation, using numerical solutions of the inhomogeneous Einstein field equations. We compared our results to perturbative calculations…
We study the influence of reheating on super-horizon density perturbations and gravitational waves. We correct wrong claims [L. P. Grishchuk Phys. Rev. D 50, 7154 (1994) and gr-qc/9801011] about the joining of perturbations at cosmological…
We investigate the problem of perturbative reheating and its effects on the evolution of the curvature perturbations in tachyonic inflationary models. We derive the equations governing the evolution of the scalar perturbations for a system…
We examine the particle production via preheating at the end of inflation in supersymmetric theories. The inflaton and matter scalars are now necessarily complex fields, and their relevant interactions are restricted by holomorphy. In…
We compute the power spectrum of super-horizon curvature perturbations generated during a late period of thermal inflation, taking into account fluctuation-dissipation effects resulting from the scalar flaton field's interactions with the…
Using the techniques of out-of-equilibrium field theory, we study the influence on the properties of cosmological perturbations generated during inflation on observable scales coming from fluctuations corresponding today to scales much…
Metric perturbations typically strengthen field resonances during preheating. In contrast we present a model in which the super-Hubble field resonances are completely {\em suppressed} when metric perturbations are included. The model is the…
We analyse models of inflation in which isocurvature perturbations present during inflation are converted into the primordial curvature perturbation during instant preheating. This can be due to an asymmetry between the fields present…
The existence of cosmological perturbations of wavelength larger than the Hubble radius is a generic prediction of the inflationary paradigm. We provide the derivation beyond perturbation theory of a conserved quantity which generalizes the…
We present a new general mechanism for generating curvature perturbations after inflation. Our model is based on the simple assumption that a field that starts to oscillate after inflation has a potential characterized by an underlying…
The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant…