相关论文: An emergent universe supported by a nonlinear sigm…

Inert Doublet Model (IDM) is a minimal extension of the Standard Model with the second scalar doublet that may provide a Dark Matter candidate. In this paper we consider the different variants of the evolution of the Universe after…

The purpose of this work is to demonstrate how an arbitrarily chosen background of the Universe can be made a solution of a simple geometric sigma model. Geometric sigma models are purely geometric theories in which spacetime coordinates…

The chaotic inflationary model of the early universe, proposed by Linde is explored in the brane world considering matter described by a minimally coupled self interacting scalar field. We obtain cosmological solutions which admit evolution…

We consider the dynamics of a contracting universe ruled by two minimally coupled scalar fields with general exponential potentials. This model describes string-inspired scenarios in the Einstein frame. Both background and perturbations can…

In this work, I have considered that the universe is filled with normal matter and phantom field (or tachyonic field). If the universe is filled with scalar field, Ellis et al have shown that emergent scenario is possible only for $k=+1$…

Observations indicate that the universe is effectively flat, but they do not rule out a closed universe. The role of positive curvature is negligible at late times, but can be crucial in the early universe. In particular, positive curvature…

Nonlinear electrodynamics with two dimensional parameters is studied. The range of electromagnetic fields when principles of causality, unitarity and the classical stability hold, are obtained. A singularity of the electric field at the…

We explore an effective 4D cosmological model for the universe where the variable cosmological constant governs its evolution and the pressure remains negative along all the expansion. This model is introduced from a 5D vacuum state where…

Matrix models of Yang-Mills type lead to an emergent gravity theory, which may not require fine-tuning of a cosmological constant. We find cosmological solutions of Friedmann-Robertson-Walker type. They generically have a big bounce, and an…

Inflationary models, especially those with plateau-type potentials, are consistent with the cosmological data, but inflation itself does not resolve the initial singularity. This singularity is resolved, for example, by the idea of the…

Three models with nonlinear realizations of conformal symmetry are discussed. The simplest model can only describe a universe expanding with a deceleration and does not include inflation. The other models are equivalent up to a variables…

The flat anisotropic model of the early Universe is considered. Two interacting scalar fields with special form of potential energy are a source of matter fields. Analytic solutions for inflationary and scalaron stages are found. It is…

In this paper we study emergent universe model in the context of a self interacting Jordan-Brans-Dicke theory. The model presents a stable past eternal static solution which eventually enters a phase where the stability of this solution is…

In this review article we consider three most important sources of the gravitational field of the Early Universe: self-interacting scalar field, chiral field and gauge field. The correspondence between all of them are pointed out. More…

The dynamics of a universe dominated by a self-interacting nonminimally coupled scalar field are considered. The structure of the phase space and complete phase portraits are given. New dynamical behaviors include superinflation…

This paper consider an universe dominated by baryonic matter, radiation and a nonminimally coupled massive scalar field under the action of a symmetry breaking potential. Inflation occurs naturally with appropriated slow-roll values. The…

A mathematical model of the Universe evolution, based on asymmetric doublet of classical and phantom dcalar Higgs fields with a kinetic connection between the components, has been constructed and studied. A detailed qualitative analysis was…

We discuss various models of inflationary universe with $\Omega \not = 1$. A homogeneous universe with $\Omega > 1$ may appear due to creation of the universe "from nothing" in the theories where the effective potential becomes very steep…

A short introduction to cosmological models that go from an era of accelerated collapse to an expanding era without displaying a singularity is presented.

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…