Related papers: Dissipative Inflation via Scalar Production
The zero temperature effective equation of motion is derived for a scalar field interacting with other fields. For a broad range of cases, involving interaction with as few as one or two fields, dissipative regimes are found for the scalar…
A compelling way to address the inflationary period is via the warm inflation scenario, where the interaction of the inflaton field with other degrees of freedom affects its dynamics in such a way that slow-roll inflation is maintained by…
Warm inflation, its different particle physics model implementations and the implications of dissipative particle production for its cosmology are reviewed. First, we briefly present the background dynamics of warm inflation and contrast it…
During cosmological inflation, it has been suggested that fields coupled to the inflaton can be excited by the slow-rolling inflaton into a quasi-stable non-vacuum state. Within this scenario of ``warm inflation'', this could allow for a…
In inflationary cosmology, the particles constituting the Universe are created after inflation in the process of reheating due to the interaction with the oscillating inflaton field. We briefly review the basics of the slow reheating, and…
We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…
In this note we point out that, contrary to the standard point of view, slow roll inflation is due to high gravitational friction. We show that the requirement of slow roll coincides with the requirement of a flat scalar field potential in…
We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct…
We revisit the possibility of producing observable tensor modes through a continuous particle production process during inflation. Particularly, we focus on the multi-field realization of inflation where a spectator pseudo-scalar $\sigma$…
We revisit the study of the phenomenology associated to a burst of particle production of a field whose mass is controlled by the inflaton field and vanishes at one given instance during inflation. This generates a bump in the correlators…
Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…
Canonical models of single-field, slow-roll inflation do not lead to appreciable non-Gaussianity, unless derivative interactions of the inflaton become uncontrollably large. We propose a novel slow-roll scenario where scalar perturbations…
It has recently been realized that many theories of physics beyond the Standard Model give rise to cosmological histories exhibiting extended epochs of cosmological stasis. During such epochs, the abundances of different energy components…
We show that Inflation in a False Vacuum becomes viable in the presence of a spectator scalar field non minimally coupled to gravity. The field is unstable in this background, it grows exponentially and slows down the pure de Sitter phase…
We revisit the efficiency of Schwinger mechanism in creating charged pairs during inflation. We consider a minimal setup of inflation in which the inflaton field is a complex scalar field charged under a $U(1)$ gauge field. There is a time…
This thesis is dedicated to studying cosmological inflation, which is a period of accelerated expansion in the very early Universe that is required to explain the observed anisotropies in the cosmic microwave background. Inflation, when…
We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…
We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators in the effective action which is constrained solely by invariance under…
We propose a model for early universe cosmology without the need for fundamental scalar fields. Cosmic acceleration and phenomenologically viable reheating of the universe results from a series of energy transitions, where during each…
A viable model for inflation driven by a torsion function in a Friedmann background is presented. The scalar spectral index in the interval $0.92\lesssim n_{s}\lesssim 0.97$ is obtained in order to satisfy the initial conditions for…