Related papers: Global Inflation Dynamics: regularities & forecast…
In models of natural inflation, the inflaton is an axion-like particle. Unfortunately, axion potentials in UV-complete theories appear to be too steep to drive inflation. We show that, even for a steep potential, natural inflation can occur…
There is very strong circumstantial evidence that there was an inflationary epoch very early in the history of the universe. In this lecture I will describe how we might be able to piece together some understanding of the dynamics during…
We study inflationary potentials in the framework of superstring theories. Successful inflation may occur due to chiral fields, but only after the dilaton and moduli are stabilized. This is achieved by demanding an S-duality invariant…
Inflationary models, especially those with plateau-type potentials, are consistent with the cosmological data, but inflation itself does not resolve the initial singularity. This singularity is resolved, for example, by the idea of the…
We investigate the end of the inflationary period in the recently proposed scenario of locked inflation, and consider various constraints arising from density perturbations, loop corrections, parametric resonance and defect formation. We…
A remarkable prediction of the Standard Model is that, in the absence of corrections lifting the energy density, the Higgs potential becomes negative at large field values. If the Higgs field samples this part of the potential during…
In the present work we study the consequences of considering a new family of single-field inflation models, called power-law plateau inflation, in the warm inflation framework. We consider the inflationary expansion is driven by a standard…
Usually inflation ends either by a slow rolling of the inflaton field, which gradually becomes faster and faster, or by a first-order phase transition. We describe a model where inflation ends in a different way, due to a very rapid rolling…
Using only general properties of the tachyon potential we show that inflation may be generic when many branes and anti-branes become coincident. Inflation may occur because of: (1) the assistance of the many diagonal tachyon fields; (2)…
We explore the possibility that inflation is driven by supersymmetry breaking with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Moreover, we impose an R-symmetry that allows to satisfy easily the…
I summarize the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by…
The phantom inflation predicts a slightly blue spectrum of tensor perturbation, which might be tested in coming observations. In normal inflation models, the introduction of step in its potential generally results in an oscillation in the…
We consider an extension of Higgs inflation in which the Higgs field is non-minimally coupled to gravity through its kinetic term. We analyzed power-law coupling functions with positive or negative integer power and found that the Higgs…
A continuous process of creation of particles is investigated as a possible connection between the inflationary stage with late cosmic acceleration. In this model, the inflationary era occurs due to a continuous and fast process of creation…
It is likely that the Higgs potential of the Standard Model is unstable, turning negative at $\phi < \Lambda \sim 10^{10}$ GeV. Here we consider whether it is possible to have Higgs Inflation on the positive stable region of the potential…
We revisit the time evolution of a flat and non-flat direction system during inflation. In order to take into account quantum noises in the analysis, we base on stochastic formalism and solve coupled Langevin equations numerically. We focus…
I describe a recently derived stochastic approach to inflaton dynamics which can address some serious problems associated with conventional inflationary theory. Using this theory I derive an exact solution to the stochastic dynamics for the…
We consider trapped inflation in a higher dimensional field space: particle production at a dense distribution of extra species points leads to a terminal velocity at which inflation can be driven in steep potentials. We compute an…
The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the…
The pre-big bang's inflationary mechanism, when allowance is made for the rapid change of Newton's constant, is not actually of pole-law form . We give examples where pole-law inflation, which requires violation of the weak-energy…