scholarly journals SIMPLEST COSMOLOGICAL MODEL WITH THE SCALAR FIELD II.

1998 ◽  
Vol 07 (01) ◽  
pp. 129-138 ◽  
Author(s):  
A. YU. KAMENSHCHIK ◽  
I. M. KHALATNIKOV ◽  
A. V. TOPORENSKY
Keyword(s):  
Phase Space ◽  
Scalar Field ◽  
Cosmological Model ◽  
Qualitative Analysis ◽  
Cosmological Constant ◽  
Numerical Calculations ◽  
Inflaton Field ◽  
Model Combining ◽  
Friedmann Robertson Walker

Continuing the investigation of the simplest cosmological model with the massive real scalar noninteracting inflaton field minimally coupled to gravity, we study an influence of the cosmological constant on the behavior of trajectories in closed minisuperspace Friedmann–Robertson–Walker model. Combining numerical calculations with qualitative analysis both in configuration and phase space we present a convenient classification of trajectories.

scholarly journals Simplest Cosmological Model with the Scalar Field

1997 ◽  
Vol 06 (06) ◽  
pp. 673-691 ◽  
Author(s):  
A. Yu. Kamenshchik ◽  
I. M. Khalatnikov ◽  
A. V. Toporensky
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Numerical Calculations ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Fractal Nature ◽  
Inflaton Field ◽  
Exactly Solvable ◽  
Friedmann Robertson Walker

We investigate the simplest cosmological model with the massive real scalar non-interacting inflaton field minimally coupled to gravity. The classification of trajectories in closed minisuperspace Friedmann–Robertson–Walker model is presented. The possible fractal nature of a set of infinitely bounced trajectories is discussed. The results of numerical calculations are compared with those obtained by perturbative analytical calculations around the exactly solvable minisuperspace cosmological model with massless scalar field.

scholarly journals Quadratic integrals of a multi-scalar cosmological model

2020 ◽  
Vol 35 (10) ◽  
pp. 2050068 ◽  
Author(s):  
Sameerah Jamal
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Conservation Laws ◽  
Analytical Solutions ◽  
Physical System ◽  
Noether Symmetries ◽  
Spatial Curvature ◽  
Special Case ◽  
Friedmann Robertson Walker ◽  
Field Integral

In the context of Friedmann–Robertson–Walker (FRW) spacetime with zero spatial curvature, we consider a multi-scalar tensor cosmology model under the pretext of obtaining quadratic conservation laws. We propose two new interaction potentials of the scalar field. Integral to this task is the existence of dynamical Noether symmetries which are Lie–Bäcklund transformations of the physical system. Finally, analytical solutions of the field are found corresponding to each new model. In one of the models, we find that the scale factor mimics [Formula: see text]-cosmology in a special case.

Non-Minimally Conformally Coupling Cosmology with Multiple Vacua Potential with Cubic-Quintic-Septic Duffing Oscillator Properties

2015 ◽  
Vol 70 (9) ◽  
pp. 685-694 ◽  
Author(s):  
Rami Ahmad El-Nabulsi
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Duffing Oscillator ◽  
Scalar Potential ◽  
Frw Cosmological Model ◽  
Friedmann Robertson Walker

AbstractThe dynamics of a flat Friedmann–Robertson–Walker (FRW) cosmological model with a barotropic matter is studied, which is dominated by an oscillating scalar field conformally coupled to the gravity with a scalar potential characterised by multiple vacua. Several motivating consequences are observed and discussed accordingly.

scholarly journals SIGNATURE CHANGE BY GUP

2013 ◽  
Vol 22 (05) ◽  
pp. 1350026 ◽  
Author(s):  
T. GHANEH ◽  
F. DARABI ◽  
H. MOTAVALLI
Keyword(s):  
Phase Space ◽  
Scalar Field ◽  
Cosmological Constant ◽  
Generalized Uncertainty Principle ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Massive Scalar ◽  
Good Correspondence ◽  
Massive Scalar Field ◽  
Frw Metric

We revisit the issue of continuous signature transition from Euclidean to Lorentzian metrics in a cosmological model described by Friedmann–Robertson–Walker (FRW) metric minimally coupled with a self-interacting massive scalar field. Then, using a noncommutative (NC) phase space of dynamical variables deformed by generalized uncertainty principle (GUP), we show that the signature transition occurs even for a model described by the FRW metric minimally coupled with a free massless scalar field accompanied by a cosmological constant. This indicates that the continuous signature transition might have been easily occurred at early universe just by a free massless scalar field, a cosmological constant and a NC phase space deformed by GUP, without resorting to a massive scalar field having an ad hoc complicate potential. We also study the quantum cosmology of the model and obtain a solution of Wheeler–DeWitt (WD) equation which shows a good correspondence with the classical path.

scholarly journals Complex Inflaton Field in Quantum Cosmology

1997 ◽  
Vol 06 (06) ◽  
pp. 649-671 ◽  
Author(s):  
A. Yu. Kamenshchik ◽  
I. M. Khalatnikov ◽  
A. V. Toporensky
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Equations Of Motion ◽  
Inflationary Cosmology ◽  
Complex Scalar ◽  
Inflaton Field ◽  
Absolute Value ◽  
Forbidden Regions ◽  
Complex Scalar Field ◽  
The Universe

We investigate the cosmological model with the complex scalar self-interacting inflaton field non-minimally coupled to gravity. The different geometries of the Euclidean classically forbidden regions are represented. The instanton solutions of the corresponding Euclidean equations of motion are found by numerical calculations supplemented by the qualitative analysis of Lorentzian and Euclidean trajectories. The applications of these solutions to the no-boundary and tunneling proposals for the wave function of the Universe are studied. Possible interpretation of obtained results and their connection with inflationary cosmology is discussed. The restrictions on the possible values of the new quasifundamental constant of the theory — non-zero classical charge — are obtained. The equations of motion for the generalized cosmological model with complex scalar field are written down and investigated. The conditions of the existence of instanton solutions corresponding to permanent values of an absolute value of scalar field are obtained.

scholarly journals Massive Spin Zero Fields in Cosmology and the Tail-Free Property

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Valerio Faraoni
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Wave Equations ◽  
Coupling Constant ◽  
De Sitter ◽  
Field Mass ◽  
Curved Space ◽  
Inflaton Field ◽  
Massive Spin ◽  
Huygens Principle

Fields of spin s ≥ 1 / 2 satisfying wave equations in a curved space obey the Huygens principle under certain conditions clarified by a known theorem. Here, this theorem is generalized to spin zero and applied to an inflaton field in de Sitter-like space, showing that tails of scalar radiation are an unavoidable physical feature. Requiring the absence of tails, on the contrary, necessarily implies an unnatural tuning between cosmological constant, scalar field mass, and coupling constant to the curvature.

scholarly journals Qualitative Analysis of the Dynamics of a Two-Component Chiral Cosmological Model

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 195
Author(s):  
Viktor Zhuravlev ◽  
Sergey Chervon
Keyword(s):  
Asymptotic Behavior ◽  
Cosmological Model ◽  
Qualitative Analysis ◽  
Critical Points ◽  
Scalar Fields ◽  
Two Component ◽  
Different Types ◽  
Asymptotic Dynamics

We present a qualitative analysis of chiral cosmological model (CCM) dynamics with two scalar fields in the spatially flat Friedman–Robertson–Walker Universe. The asymptotic behavior of chiral models is investigated based on the characteristics of the critical points of the selfinteraction potential and zeros of the metric components of the chiral space. The classification of critical points of CCMs is proposed. The role of zeros of the metric components of the chiral space in the asymptotic dynamics is analysed. It is shown that such zeros lead to new critical points of the corresponding dynamical systems. Examples of models with different types of zeros of metric components are represented.

CHAOS IN SIMPLE COSMOLOGICAL MODELS

1994 ◽  
Vol 03 (01) ◽  
pp. 167-170
Author(s):  
ESTEBAN CALZETTA
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Time Scales ◽  
Chaotic Behavior ◽  
Information Loss ◽  
Field Amplitude ◽  
Phase Changes ◽  
Cosmological Time ◽  
Nonlinear Phase ◽  
Friedmann Robertson Walker

We study the occurrence of chaotic behavior in a simple cosmological model, consisting of a spatially closed Friedmann-Robertson-Walker universe filled with a conformally coupled but massive real scalar field, Chaos sets in when the field amplitude is large enough, in the guise of strong variability in the phase of the field oscillations. These nonlinear phase changes may cause significative information loss within cosmological time scales.

scholarly journals Deformation of the quintom cosmological model and its consequences

2018 ◽  
Vol 27 (03) ◽  
pp. 1850025 ◽  
Author(s):  
J. Sadeghi ◽  
B. Pourhassan ◽  
Z. Nekouee ◽  
M. Shokri
Keyword(s):  
Dark Energy ◽  
Phase Space ◽  
Cosmological Model ◽  
Cosmological Constant ◽  
Cosmological Parameters ◽  
Time Dependent ◽  
Noether Symmetry ◽  
Noncommutative Phase Space ◽  
Deformation Parameters ◽  
Noncommutative Parameter

In this paper, we investigate the effects of noncommutative phase-space on the quintom cosmological model. In that case, we discuss about some cosmological parameters and show that they depend on the deformation parameters. We find that the noncommutative parameter plays important role which helps to re-arrange the divergency of cosmological constant. We draw time-dependent scale factor and investigate the effect of noncommutative parameters. Finally, we take advantage from noncommutative phase-space and obtain the deformed Lagrangian for the quintom model. In order to discuss some cosmological phenomena as dark energy and inflation, we employ Noether symmetry.

Sign in / Sign up

Export Citation Format

Share Document