相关论文: Intermediate inflation or late time acceleration?
Inflation is considered to be the best paradigm for describing the early universe. However, it is still unclear what is the nature of the field which drives inflation. In this talk, we discuss the possibility of spinor field driving…
It is widely accepted that the primordial universe experienced a brief period of accelerated expansion called inflation. This scenario provides a plausible solution to the horizon and flatness problems. However, the particle physics…
We propose a scenario where inflation is driven by non-minimally coupled massive vector fields. In an isotropic homogeneous universe these fields behave in presicely the same way as a massive minimally coupled scalar field. Therefore our…
The expansion of the Universe is understood to have accelerated during two epochs: in its very first moments during a period of Inflation and much more recently, at $z < 1$, when Dark Energy is hypothesized to drive cosmic acceleration. The…
Quantum gravity computations suggest the existence of an ultraviolet and an infrared fixed point where quantum scale invariance emerges as an exact symmetry. We discuss a particular variable gravity model for the crossover between these…
We investigate warm inflationary scenario in which the accelerated expansion of the early Universe is driven by chameleon-like scalar fields. Due to the non-minimal coupling between the scalar field and the matter sector, the…
A model is presented in which a single scalar field is responsible for both primordial inflation at early times and then dark energy at late times. This field is coupled to a second scalar field which becomes unstable and starts to…
Preheating after inflation may lead to nonthermal phase transitions with symmetry restoration. These phase transitions may occur even if the total energy density of fluctuations produced during reheating is relatively small as compared with…
The mechanism of thermal inflation, a relatively short period of accelerated expansion after primordial inflation, is a desirable ingredient for a certain class of particle physics models if they are not to be in contention with the…
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…
To derive a power spectrum for energy density inhomogeneities in a closed universe, we study a spatially-closed inflation-modified hot big bang model whose evolutionary history is divided into three epochs: an early slowly-rolling scalar…
The present epoch of accelerated cosmic expansion is supposed to be driven by an unknown constituent called dark energy, which in the standard model takes the form of a cosmological constant, characterized by a constant equation of state…
We argue that $\Lambda$-driven inflation must overshoot into an era of deflation. The deflationary period ends quickly with the creation of a hot dense thermal barrier to the forward propagation of quantum correlations from the period of…
The increasing interest in studying the role of holographic dark energy in the evolution of the very early universe motivates us to study it for the scenario of warm inflation. Due to this scenario, the holographic dark energy, which now…
The situation that a scalar field provides the source of the accelerated expansion of the universe while rolling down its potential is common in both the simple models of the primordial inflation and the quintessence-based dark energy…
There is now overwhelming observational evidence that our Universe is accelerating in its expansion. I discuss how modified gravitational models can provide an explanation for this observed late-time cosmic acceleration. We consider…
In recent years different explanations are provided for both an inflation and a recent acceleration in the expansion of the universe. In this Letter we show that a model of physical interest is the modification of general relativity with a…
In this paper, we study early-time inflation and late-time acceleration of the universe by non-minimally coupling the Dirac field with torsion in the spatially flat Friedman-Robertson-Walker (FRW) cosmological model background. The results…
Extended inflation is a promising new approach to implementing the inflationary universe scenario. This paper reviews recent advances including a new, more robust mechanism for ending extended inflation, a new prediction for the density…
In this paper, we demonstrate that a unified description of early and late-time acceleration is possible in the context of mimetic $F(R)$ gravity. We study the inflationary era in detail and demonstrate that it can be realized even in…