Related papers: From Inflation to Dark Energy
We propose an inflation scenario with three independent stages of cold, warm and thermal inflation, respectively, driven by different scalar fields, motivated by the large number of such fields predicted in most extensions of the Standard…
The current epoch of accelerated cosmic expansion is postulated to be driven by dark energy, which in the standard model takes the form of a cosmological constant with equation of state parameter $w=-1$. We propose an innovative perspective…
We consider the oscillating dark energy with periodic equation of state in two equivalent formulations: ideal fluid or scalar-tensor theory. It is shown that such dark energy suggests the natural way for the unification of early-time…
In this paper we consider a new approach to unify inflation and the late universe with dark energy and dark matter formulated in a model that includes a non-Riemannian metric independent measure and a scalar field with spontaneously broken…
Inflation universally produces classical almost scale free Gaussian inhomogeneities of any light scalars. Assuming the coupling constants at the time of inflation depend on some light moduli fields, we encounter the generation of modulated…
The empty space (with no matter fields) is not really empty because of natural metric fluctuations, quantum and classical. We show that gravitons as well as classical gravitational waves of super-horizon wavelengths are able to form the de…
The fluctuations in the inflaton field at the end of inflation which seed the density perturbations are prepared in a pure quantum state. It is generally assumed that some physics causes this pure state to decohere so that it should be…
A gravity-driven inflation is shown to arise from a simple higher dimensional universe. In vacuum, the shear of $n>1$ contracting dimensions is able to inflate the remaining three spatial dimensions. Said another way, the expansion of the…
We perform a systematic analysis of dark matter production during post-inflationary reheating. Following the period of exponential expansion, the inflaton begins a period of damped oscillations as it decays. These oscillations and the…
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…
Cosmological reheating bridges the inflationary epoch and the hot big bang phase, yet its underlying dynamics remain poorly understood. In this work, we investigate a minimal scenario in which the inflaton evolves under a simple power-law…
Motivated by the work of Nojiri et al. (2019) [S. Nojiri, S. D. Odintsov and E. N. Saridakis, Holographic inflation, Phys. Lett. B 797 (2019) 134829], the present study reports a model of inflation under the consideration that the…
Cosmological inflation provides the simplest and most promising mechanism for generating fluctuations for structure formation. Using powerful Hamilton-Jacobi methods, I will describe (1) how to compute density fluctuations and cosmic…
The energy density correlation function $C(x,y)=<\rho(x)\rho(y)>-<\rho>^2$ and its Fourier transform generated by the gravitational tidal forces of the inflationary de Sitter expansion are derived for a massless or light ($m<<H$) neutral…
It is shown that quantum vacuum fluctuations give rise to a curvature of space-time of the order appropriate to explain the observed accelerated expansion of the universe. The fact that the fluctuations produce curvature, even if the…
The notion of inflation (past or present) in standard cosmological models is shown to be a consequence of a sufficiently high second law entropy production from the internal heating of the universal expansion. The longitudinal viscous…
We examine the spectrum of inflaton fluctuations resulting from any given long period of exponential inflation. Infrared and ultraviolet divergences in the inflaton dispersion summed over all modes do not appear in our approach. We show how…
The emergence of Hawking radiation from vacuum fluctuations is analyzed in conventional field theories and their energy content is defined through the Aharonov weak value concept. These fluctuations travel in flat space-time and carry…
Due to intra-field gravitational interactions, field configurations have a strong negative component to their energy density at the planckian and transplanckian scales, conceivably resulting in a sequestration of the transplanckian field…
Reheating after inflation can occur through inflaton decay or efficient parametric resonant production of particles from the oscillation of the inflaton. If the particles produced interact with scalars that were light during inflation, then…