相关论文: Free light fields can change the predictions of hy…
Inflation offers a simple model for very early evolution of our Universe and the origin of primordial perturbations on large scales. Over the last 25 years we have become familiar with the predictions of single-field models, but inflation…
In this paper we study the inflation model driven by the phantom field. We propose a possible exit from phantom inflation to our observational cosmology by introducing an additional normal scalar field, similar to hybrid inflation model.…
In inflationary scenarios with more than one scalar field, inflation may proceed even if each of the individual fields has a potential too steep for that field to sustain inflation on its own. We show that scalar fields with exponential…
In the inflationary universe, there can be light fields other than the inflaton. We explore a possibility that such light fields source the primordial perturbations, while minimally affecting the inflaton dynamics. We show that during…
Two extensions of ideas lying in the basis of the inflationary scenario of the early Universe and their effect on the large scale structure of the present-day Universe are discussed. The first of them is the possibility of fast phase…
Out-of-equilibrium, non-perturbative, quantum effects significantly modify the standard picture of inflation in a wide class of models including new, natural, and hybrid inflation. We find that the quantum evolution of a single real…
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…
We generalize the Effective Field Theory of Inflation to include additional light scalar degrees of freedom that are in their vacuum at the time the modes of interest are crossing the horizon. In order to make the scalars light in a natural…
We investigate the range of inflationary universe models driven by scalar fields possessing a general interaction potential of the form $V(\phi) = V_0 \phi^n \exp(-\lambda \phi^m)$. Power-law, de Sitter and intermediate inflationary…
Nowadays cosmological inflation is the most accepted mechanism to explain the primordial seeds that led to the structure formation observed in the Universe. Current observations are in well agreement to initial adiabatic conditions, which…
A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale invariant theory of gravity involving two scalar fields -…
Light scalar fields present during inflation can lead to interesting observable signatures, especially in models with non-equilibrium reheating dynamics. We study a supersymmetric hybrid inflation model with a third scalar whose lightness…
Scalar fields appear in many cosmological models, in particular in order to provide explanations for dark energy and inflation, but also to emulate dark matter. In this paper, we show that it is possible for a scalar field to replace…
We propose one way to regularize the fluctuations generated during inflation, whose infrared (IR) corrections diverge logarithmically. In the case of a single field inflation model, recently, we proposed one solution to the IR divergence…
The latest results from PLANCK impose strong constraints on features in the spectrum of the curvature perturbations from inflation. We analyse the possibility of particle production induced by sharp turns of the trajectory in field space in…
Light fields get large scale fluctuations during inflation. If some of them are electrically charged, then large scale fluctuations of the electric charge will be generated. As a consequence, any finite portion of the Universe, including…
Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient…
In the framework of chaotic inflation we study the case of a massive scalar field using a semiclassical approach. We derive the energy density fluctuations in the infrared sector generated by matter field and gauge-invariant metric…
Effects caused by an additional massive scalar field interacting with an inflaton field are analyzed. Inflation is shown to have two stages, the first of which is dominant and characterized by ultraslow dynamics of the inflaton field.…
Primordial non-Gaussianity generated by additional fields present during inflation offers a compelling observational target for galaxy surveys. These fields are of significant theoretical interest since they offer a window into particle…