scholarly journals Method of multiple scales in scalar field cosmology

2021 ◽  
Vol 2081 (1) ◽  
pp. 012037
Author(s):  
V M Zhuravlev ◽  
S V Chervon
Keyword(s):  
Scalar Field ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
General Scheme ◽  
Small Field ◽  
Slow Roll ◽  
Different Types ◽  
Walker Metric ◽  
Scalar Field Cosmology ◽  
The Universe

Abstract In this work, the method of multiple scales is applied to analysis of cosmological dynamics. The method is used to construct solutions to the dynamic equations of the Universe filled with a scalar field in the Friedman-Robertson-Walker metric. A general scheme is described for choosing small dimensionless parameters of the expansion of model functions and applying the method itself to the equations of cosmological dynamics. Solutions are given that are constructed for two different types of a small parameter - a small field value and a small slow roll parameter.

scholarly journals Scalar field cosmology in Lyra's geometry

2015 ◽  
Vol 3 (2) ◽  
pp. 117 ◽  
Author(s):  
V. K. Shchigolev ◽  
E. A. Semenova
Keyword(s):  
Exact Solution ◽  
Scalar Field ◽  
Generating Function ◽  
Function Method ◽  
Scalar Fields ◽  
First Order ◽  
Homogeneous Cosmological Models ◽  
Different Types ◽  
Lyra’S Geometry ◽  
Scalar Field Cosmology

<p>The new classes of homogeneous cosmological models for the scalar fields are build in the context of Lyra’s geometry. The different types of exact solution for the model are obtained by applying two procedures, viz the generating function method and the first order formalism.</p>

scholarly journals Chameleon field dynamics during inflation

2018 ◽  
Vol 27 (04) ◽  
pp. 1850041 ◽  
Author(s):  
Nasim Saba ◽  
Mehrdad Farhoudi
Keyword(s):  
Scalar Field ◽  
Equation Of State ◽  
State Parameter ◽  
Big Bang ◽  
Late Time ◽  
Inflationary Model ◽  
Slow Roll ◽  
Equation Of State Parameter ◽  
The Common ◽  
The Universe

By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll approximations, we obtain the e-folding number for the model to verify the ability of resolving the problems of standard big bang cosmology. Meanwhile, we apply the constraints on the form of the chosen potential and also on the equation of state parameter coupled to the scalar field. However, the results of the present analysis show that there is not much chance of having the chameleonic inflation. Hence, we suggest that if through some mechanism the chameleon model can be reduced to the standard inflationary model, then it may cover the whole era of the universe from the inflation up to the late time.

THE ROLE OF A CHAMELEON FIELD IN AN ANISOTROPIC UNIVERSE WITH LOGAMEDIATE AND INTERMEDIATE SCENARIOS

2010 ◽  
Vol 25 (24) ◽  
pp. 4691-4701 ◽  
Author(s):  
SHUVENDU CHAKRABORTY ◽  
UJJAL DEBNATH
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Anisotropic Universe ◽  
Anisotropic Model ◽  
Scale Factors ◽  
Slow Roll ◽  
Energy Scalar ◽  
The Universe

In this work, we consider the Universe is being filled with matter composed of a chameleon-type dark energy scalar field. Employing a particular form of potential, we discuss the field's role in the accelerating phase of the Universe for an anisotropic model using the logamediate and intermediate forms of scale factors. The natures of statefinder and slow-roll parameters are discussed diagrammatically.

scholarly journals The Great Chains of Computing: Informatics at Multiple Scales

2011 ◽  
Vol 9 (2) ◽  
pp. 434-443
Author(s):  
Kevin Kirby ◽  
James Walden ◽  
Rudy Garns ◽  
Maureen Doyle
Keyword(s):  
Social Networks ◽  
Information Processing ◽  
Multiple Scales ◽  
Quantum Level ◽  
Western Thought ◽  
Different Types ◽  
Great Chain Of Being ◽  
Characteristic Features ◽  
The Universe

The perspective from which information processing is pervasive in the universe has proven to be an increasingly productive one. Phenomena from the quantum level to social networks have commonalities that can be usefully explicated using principles of informatics. We argue that the notion of scale is particularly salient here. An appreciation of what is invariant and what is emergent across scales, and of the variety of different types of scales, establishes a useful foundation for the transdiscipline of informatics. We survey the notion of scale and use it to explore the characteristic features of information statics (data), kinematics (communication), and dynamics (processing). We then explore the analogy to the principles of plenitude and continuity that feature in Western thought, under the name of the "great chain of being", from Plato through Leibniz and beyond, and show that the pancomputational turn is a modern counterpart of this ruling idea. We conclude by arguing that this broader perspective can enhance informatics pedagogy.

scholarly journals The Great Chains of Computing: Informatics at Multiple Scales

2011 ◽  
Vol 9 (2) ◽  
pp. 434-443
Author(s):  
Kevin Kirby ◽  
James Walden ◽  
Rudy Garns ◽  
Maureen Doyle
Keyword(s):  
Social Networks ◽  
Information Processing ◽  
Multiple Scales ◽  
Quantum Level ◽  
Western Thought ◽  
Different Types ◽  
Great Chain Of Being ◽  
Characteristic Features ◽  
The Universe

The perspective from which information processing is pervasive in the universe has proven to be an increasingly productive one. Phenomena from the quantum level to social networks have commonalities that can be usefully explicated using principles of informatics. We argue that the notion of scale is particularly salient here. An appreciation of what is invariant and what is emergent across scales, and of the variety of different types of scales, establishes a useful foundation for the transdiscipline of informatics. We survey the notion of scale and use it to explore the characteristic features of information statics (data), kinematics (communication), and dynamics (processing). We then explore the analogy to the principles of plenitude and continuity that feature in Western thought, under the name of the "great chain of being", from Plato through Leibniz and beyond, and show that the pancomputational turn is a modern counterpart of this ruling idea. We conclude by arguing that this broader perspective can enhance informatics pedagogy.

scholarly journals Inflation from Supersymmetry Breaking

Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 30 ◽  
Author(s):  
Ignatios Antoniadis
Keyword(s):  
Supersymmetry Breaking ◽  
Vacuum Energy ◽  
Scalar Potential ◽  
Small Field ◽  
Slow Roll ◽  
Cosmological Observations ◽  
Interesting Class ◽  
The Universe ◽  
R Symmetry

I discuss the possibility that inflation is driven by supersymmetry breaking, with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Imposing an R-symmetry to satisfy the slow-roll conditions, avoiding the so-called η -problem, leads to an interesting class of small field inflation models, characterised by an inflationary plateau around the maximum of scalar potential near the origin, where R-symmetry is restored with the inflaton rolling down to a minimum, describing the present phase of the Universe. Inflation can be driven by either an F- or a D-term, while the minimum has a positive tuneable vacuum energy. The models agree with cosmological observations and, in the simplest case, predict a rather small tensor-to-scalar ratio of primordial perturbations. This talk is an extended version of an earlier review (Antoniadis, 2018).

scholarly journals Challenges in Supersymmetric Cosmology

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 468
Author(s):  
Ignatios Antoniadis ◽  
Auttakit Chatrabhuti
Keyword(s):  
Vacuum Energy ◽  
Scalar Potential ◽  
Low Energy ◽  
Small Field ◽  
Slow Roll ◽  
Cosmological Observations ◽  
Interesting Class ◽  
The Universe ◽  
R Symmetry

We discuss the possibility that inflation is driven by supersymmetry breaking with the scalar component of the goldstino superfield (sgoldstino) playing the role of the inflaton and charged under a gauged U ( 1 ) R-symmetry. Imposing a linear superpotential allows us to satisfy easily the slow-roll conditions, avoiding the so-called η -problem, and leads to an interesting class of small field inflation models, characterised by an inflationary plateau around the maximum of the scalar potential near the origin, where R-symmetry is restored with the inflaton rolling down to a minimum describing the present phase of the Universe. Inflation can be driven by either an F- or a D-term, while the minimum has a positive tuneable vacuum energy. The models agree with cosmological observations and in the simplest case predict a rather small tensor-to-scalar ratio of primordial perturbations. We propose a generalisation of Fayet-Iliopoulos model as a microscopic model leading to this class of inflation models at low energy.

scholarly journals Gauss–Bonnet term corrections in scalar field cosmology

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Igor Fomin
Keyword(s):  
Scalar Field ◽  
Field Potential ◽  
Einstein Gravity ◽  
Minimal Coupling ◽  
Evolution Of The Universe ◽  
Scalar Field Cosmology ◽  
The Universe ◽  
Bonnet Term ◽  
Inflationary Models

AbstractThe influence of non-minimal coupling of a scalar field and the Gauss–Bonnet term on the inflationary stage of evolution of the universe is investigated in this paper. The main cosmological effects of such a coupling were considered. The deviations between Einstein–Gauss–Bonnet inflation and standard one based on Einstein gravity were determined. The corrections of a weak GB coupling preserving the type of the scalar field potential to standard inflationary models is considered as well.

Challenges in string and supersymmetric cosmology

2021 ◽  
pp. 2044030
Author(s):  
Ignatios Antoniadis ◽  
Auttakit Chatrabhuti
Keyword(s):  
Supersymmetry Breaking ◽  
Vacuum Energy ◽  
Scalar Potential ◽  
Small Field ◽  
Slow Roll ◽  
Cosmological Observations ◽  
Interesting Class ◽  
The Universe ◽  
R Symmetry

We discuss the possibility that inflation is driven by supersymmetry breaking with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Imposing an R-symmetry allows to satisfy easily the slow-roll conditions, avoiding the so-called [Formula: see text]-problem, and leads to an interesting class of small field inflation models, characterized by an inflationary plateau around the maximum of the scalar potential near the origin, where R-symmetry is restored with the inflaton rolling down to a minimum describing the present phase of the Universe. Inflation can be driven by either an [Formula: see text]- or a [Formula: see text]-term, while the minimum has a positive tuneable vacuum energy. The models agree with cosmological observations and in the simplest case predict a rather small tensor-to-scalar ratio of primordial perturbations.

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