Related papers: Exiting Inflation with a Smooth Scale Factor
Slow-roll of the inflaton field defines the standard dynamics of the inflationary epoch. However, the inflationary system deviates from slow-roll when it encounters an extremely flat region of the inflaton potential, and enters a phase…
Evolution of the scale factor a(t) in Friedmann models (those with zero pressure and a constant cosmological term Lambda) is well understood, and elegantly summarized in the review of Felten and Isaacman [Rev. Mod. Phys. 58, 689 (1986)].…
We study the most general cosmological model with real scalar field which is minimally coupled to gravity. Our calculations are based on Friedmann-Lemaitre-Robertson-Walker (FLRW) background metric. Field equations consist of three…
The scenario of two components warm tachyon inflation is considered where the tachyon field plays the role of inflaton and drives inflation. During inflation, the tachyon scalar field interacts with the other component of the Universe which…
WE analyse the universe inflation when the source of gravity is electromagnetic fields obeying nonlinear electrodynamics with two parameters and without singularities. The cosmology of the universe with stochastic magnetic fields is…
Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll…
The scale at which supersymmetry is broken and the mechanism by which supersymmetry breaking is fed down to the observable sector has rich implications on the way Nature may have chosen to accomplish inflation. We discuss a simple model for…
We show that a moduli space of the form predicted by string theory, lifted by supersymmetry breaking, gives rise to successful inflation for large regions of parameter space without any modification or fine tuning. This natural realization…
Quantum geometry predicts that a universe evolves through an inflationary phase at small volume before exiting gracefully into a standard Friedmann phase. This does not require the introduction of additional matter fields with ad hoc…
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 formulate a gradual dynamical transition from a power-law inflation era with a scalar field to a radiation era with no scalar field including inhomogeneous perturbations to the Friedmann- Robertson-Walker universe. We show that for the…
We consider an inflationary kinetic function with an integrable pole that is traversed during inflation. This scenario leads to enhanced spectra of primordial scalar inhomogeneities with detectable signals: formation of primordial black…
The energy scale of inflation is of much interest, as it suggests the scale of grand unified physics and also governs whether cosmological events such as topological defect formation can occur after inflation. The COBE results are used to…
We consider the extended supersymmetric Pati-Salam model which, for mu>0 and universal boundary conditions, succeeds to yield experimentally acceptable b-quark masses by moderately violating Yukawa unification. It is known that this model…
Scattering amplitudes at weak coupling are highly constrained by Lorentz invariance, locality and unitarity, and depend on model details only through coupling constants and particle content. In this paper, we develop an understanding of…
The interplay among the possible variation of gauge coupling and the inflationary dynamics is investigated in a simplified toy model. Depending upon various parameters (scalar mass, curvature scale at the end of inflation and at the onset…
In the warm inflation scenario, the early cosmic acceleration is driven by the inflaton coupled to thermal fields, decaying into radiation and leaving a hot universe populated by relativistic particles after the end of inflation. The…
The multi-measures model applied to cosmology has been recently shown to reproduce qualitatively the expected stages of the Universe evolution, along with some unexpected features. In this article, we continue its exploration with a…
In the framework of a flat Friedmann-Lema{\^\i}tre-Robertson-Walker (FLRW) geometry, we present a nonsingular model (no big bang singularity at finite time) of our universe describing its evolution starting from its early inflationary era…
In the context of the open inflationary universe, we calculate the amplitude of quantum fluctuations which deform the bubble shape. These give rise to scalar field fluctuations in the open Friedman-Robertson-Walker universe which is…