Related papers: Inflation and the Fine-Tuning Problem
Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple…
Brane inflation can provide a promissing framework for solving the fine-tuning problem in standard inflationary models. The aim of this paper is to illustrate the mechanism by which this can be achieved. By considering the supersymmetric…
It has been widely claimed that inflation is generically eternal to the future, even in models where the inflaton potential monotonically increases away from its minimum. The idea is that quantum fluctuations allow the field to jump uphill,…
We continue to investigate possible parameter choices for primordial inflation with simple potentials such as power-law and two-term potentials. We examine the amount of parameter tuning to make the slow-roll inflation eternal. In…
I explore properties of the inflationary flow equations. I show that the flow equations do not correspond directly to inflationary dynamics. Nevertheless, they can be used as a rather complicated algorithm for generating inflationary…
Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…
Robustness of the solutions to the inflaton potential inverse problem based on the slow-roll approximation is addressed. With that aim it is introduced a measure of the difference of the outputs obtained using first and second order…
The curvature perturbations produced during an early era of inflation are known to have quasi-Gaussian distribution functions close to their maximum, where they are well constrained by measurements of the cosmic microwave background…
These lectures cover the basics of inflationary models for the early universe, concentrating particularly on the generation of density fluctuations from scalar-field dynamics. The subsequent gravitational dynamics of these fluctuations in…
The stochastic approach aims at describing the long-wavelength part of quantum fields during inflation by a classical stochastic theory. It is usually formulated in terms of Langevin equations, giving rise to a Fokker-Planck equation for…
The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. I describe the quantum origin of density perturbations, giving a heuristic derivation of…
We consider a single scalar field inflation model with Higgs potential and curvature corrections given by non-minimal derivative coupling to gravity and coupling to the Gauss-Bonnet invariant. Exact analytical expressions, within the…
We study the power spectrum of the mass density perturbations in an inflation scenario that includes thermal dissipation. We show that the condition on which the thermal fluctuations dominate the primordial density perturbations can easily…
We present a class of models in which the primordial metric fluctuations do not necessarily obey Gaussian statistics. These models are realizations of mechanisms in which non-Gaussianity is first generated by a light scalar field and then…
The curvaton and the inhomogeneous reheating scenarios for the generation of the cosmological curvature perturbation on large scales represent an alternative to the standard slow-roll scenario where the observed density perturbations are…
We provide a formulation of Stochastic Inflation in full general relativity that goes beyond the slow-roll and separate universe approximations. We show how gauge invariant Langevin source terms can be obtained for the complete set of…
Stochastic inflation, together with the $\Delta N$ formalism, provides a powerful tool for estimating the large-scale behaviour of primordial fluctuations. In this work, we develop a numerical code to capture the non-perturbative statistics…
We argue for a model of low-energy correction to the inflationary potential as caused by the gauge-mediated breaking down the supersymmetry at the scale of $\mu_\textsc{x}\sim 10^4$ GeV, that provides us with the seesaw mechanism of thin…
We construct non-linear inflaton potential energy densities that describe not-necessarily very-slowly-rolling closed and open inflation models, and compute tilted primordial spatial inhomogeneity power spectra that follow from quantum…
Inflation, as currently understood, requires the presence of fields with very flat potentials. Supersymmetric models in which supersymmetry breaking is communicated by supergravity naturally yield such fields, but the scales are typically…