Related papers: Quantum Evolution of the Dilaton-Inflaton Model
Starting from pure multidimensional gravity with curvature-nonlinear terms but no matter fields in the initial action, we obtain a cosmological model with two effective scalar fields related to the size of two extra factor spaces. The model…
We investigate the inflationary universe in a theory where two scalar fields non-minimally coupling to the scalar curvature and an extra $R^2$ term exist and the conformal invariance is broken. In particular, the slow-roll inflation is…
We consider a non-minimally coupled inflaton, in a higher order curvature background, leading to a potential which evolves with the curvature scalar of the Universe, and which describes two regimes. The first one is a de Sitter phase, where…
Inflation models are compared with observation on the assumption that the curvature perturbation is generated from the vacuum fluctuation of the inflaton field. The focus is on single-field models with canonical kinetic terms, classified as…
We examine extended inflation models enhanced by the addition of a coupling between the inflaton field and the space-time curvature. We examine two types of model, where the underlying inflaton potential takes on second-order and…
I study two-stage hybrid inflation driven by moduli fields, corresponding to flat directions of supersymmetry, lifted by supergravity corrections. The first stage corresponds to a period of either fast-roll or `locked' inflation, induced by…
As is well known, the exact evolution equation of the curvature perturbation plays a very important role in investigation of the inflation power spectrum of the flat universe. However, its corresponding exact extension for the non-flat…
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…
Inflation has long been the accepted paradigm for understanding the early universe. Most models of inflation have a scalar field acting as the inflaton particle which decays after inflation during a process called reheating into standard…
We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…
Multiple field models of inflation exhibit new features than single field models. In this work, we study the hierarchy of parameters based on Hubble expansion rate in curved field space and derive the system of flow equations that describe…
The inflationary phase of the Universe is explored by proposing a toy model related to the scalar field, termed as {\it inflaton}. The potential part of the energy density in the said era is assumed to have a constant vacuum energy density…
Since inflationary perturbations must generically couple to all degrees of freedom present in the early Universe, it is more realistic to view these fluctuations as an open quantum system interacting with an environment. Then, on very…
We study the evolution of a quantum scalar field in a toy universe which has three stages of evolution, viz., (i) an early (inflationary) de Sitter phase (ii) radiation dominated phase and (iii) late-time (cosmological constant dominated)…
We explore the homogeneous background dynamics and the evolution of generated perturbations of cosmological inflation that is driven by multiple scalar fields interacting with a perfect fluid.Then we apply the method to warm inflation…
We study the dynamics of the quantum scalar field responsible for inflation in different epochs of the evolution of the universe by using a recently introduced nonperturbative formalism from a 5D apparent vacuum.
We consider the dynamics of tensor and scalar gravitational fields in the Relativistic Theory of Gravitation with the Minkowskian vacuum metric and generalize the formulation to the massless graviton. The potential of scalar field is…
We study inflationary universe models that are characterized by a single scalar inflaton field. The study of these models are based on two dynamical equations; one corresponding to the Klein-Gordon equation for the inflaton field, and the…
In a recent work, we demonstrated that a modified gravity model in which a scalar "darkon" field is coupled to both the standard Riemannian metric and to another non-Riemannian volume form is compatible with observational data from…
The evolution of the universe started from a hot and dense Big Bang point. Temperature fluctuation map of cosmic microwave background (CMB) radiation and initial seeds of large scale structures (LSS) are explained by an inflationary period…