Related papers: Inflation and Decoupling
Primordial fluctuations in inflationary cosmology acquire classical properties through decoherence when their wavelengths become larger than the Hubble scale. Although decoherence is effective, it is not complete, so a significant part of…
By incorporating quantum aspects of gravity, Loop Quantum Cosmology (LQC) provides a self-consistent extension of the inflationary scenario, allowing for modifications in the primordial inflationary power spectrum with respect to the…
Warm natural inflation is studied for the case of the original cosine potential. The radiation bath during inflation induces a dissipation (friction) rate in the equation of motion for the inflaton field, which can potentially reduce the…
In this paper we present a simple argument that shows a non-singular bouncing cosmology naturally yields an era of super-inflation which can precede the phase of normal potential driven inflation. One of the consequences of a…
The so-called "trans-Planckian" problem of inflation may be evaded by positing that modes come into existence only when they became "cis-Planckian" by virtue of expansion. However, this would imply that for any mode a new random realization…
We investigate the implication of Trans-Planckian Censorship Conjecture (TCC) for the initial state of primordial perturbations. It is possible to set the state of perturbation modes in the infinite past as the Minkowski vacuum, only if the…
We re-examine the decoherence rate of primordial fluctuations within minimal inflationary models, using only the gravitational interactions required for the underlying fluctuation-generation mechanism itself. Since gravity provides the…
In the framework of effective field theories with prominent helicity-0 and helicity-1 fields coupled to each other via a dimension-3 operator, we study the dynamics of inflation driven by the helicity-0 mode, with a given potential energy,…
Eternal inflation is studied in the context of warm inflation. We focus on different tools to analyze the effects of dissipation and the presence of a thermal radiation bath on the fluctuation-dominated regime, for which the…
Warm inflation is an interesting possibility of describing the early universe, whose basic feature is the absence, at least in principle, of a preheating or reheating phase. Here we analyze the dynamics of warm inflation generalizing the…
When Inflation is embedded in a fundamental theory, such as string theory, it typically begins when the Universe is already substantially larger than the fundamental scale [such as the one defined by the string length scale]. This is…
We consider small-field models which invoke the usual framework for the effective field theory, and large-field models which go beyond that. Present and future possibilities for discriminating between the models are assessed, on the…
We study the power spectrum of super-Hubble fluctuations of an inflaton-like scalar field, the "system", coupled to another scalar field, the "environment" during de Sitter inflation. We obtain the reduced density matrix for the inflaton…
We demonstrate that the strict upper bounds on the energy scale of inflation and on the tensor-to-scalar ratio can be somewhat relaxed if we assume that - after an initial period of slow rolling when scales probed today in CMB experiments…
It is investigated if predictions of the inflationary scenario regarding spectra of scalar and tensor perturbations generated from quantum vacuum fluctuations are robust with respect to a modification of the dispersion law for frequencies…
Within the framework of the scalar-tensor theory we consider a hill-climbing inflation, in which the effective Planck mass increases in time. We obtain the Einstein frame potential with infinitely long and flat plateau as we approach…
A novel approach to quintessential inflation model building is studied, within the framework of $\alpha$-attractors, motivated by supergravity theories. Inflationary observables are in excellent agreement with the latest CMB observations,…
We present a model with a complex and a real scalar fields and a potential whose symmetry is explicitly broken by Planck-scale physics. For exponentially small breaking, the model accounts for the period of inflation in the early universe…
The "de Sitter constraint" on the space of effective scalar field theories consistent with superstring theory provides a lower bound on the slope of the potential of a scalar field which dominates the evolution of the Universe, e.g., a…
We study leading order perturbative corrections to the two point correlation function of the scalar field describing the curvature perturbation in a slow-roll inflationary background, paying particular attention to the contribution of…