On braneworld inverse power-law inflation

2018 ◽  
Vol 33 (10) ◽  
pp. 1850058 ◽  
Author(s):  
H. Es-sobbahi ◽  
M. Nach
Keyword(s):  
Observational Data ◽  
Power Law ◽  
Equations Of Motion ◽  
High Energy ◽  
Type Ii ◽  
Scalar Model ◽  
Slow Roll ◽  
Inverse Power Law ◽  
Perturbation Spectrum ◽  
High Energy Regime

In the framework of the braneworld Randall–Sundrum type II model, we investigate an inflationary scalar model in the high-energy regime. In this regime, the slow-roll parameters and the perturbation spectrum of the model are derived. The corresponding results are dealt with according to the known observational data. Then the solutions to the equations of motion on the brane are given.

On braneworld monomial inflation

2018 ◽  
Vol 33 (25) ◽  
pp. 1850147
Author(s):  
R. Ahl Laamara ◽  
H. ES-SOBBAHI ◽  
S. E. Ennadifi
Keyword(s):  
Observational Data ◽  
High Energy ◽  
Equation Of Motion ◽  
Type Ii ◽  
Scalar Model ◽  
Slow Roll ◽  
Energy Regime ◽  
Perturbation Spectrum ◽  
High Energy Regime

We investigate a monomial inflationary scalar model in the braneworld Randall–Sundrum type II model. In the high-energy regime, we determine the slow-roll parameters as well as the perturbation spectrum of the model. According to the known observational data, the corresponding results and the solutions of the equation of motion on the brane are discussed.

scholarly journals WMAP5 OBSERVATIONAL CONSTRAINTS ON BRANEWORLD NEW INFLATION MODEL

2010 ◽  
Vol 25 (01) ◽  
pp. 171-183 ◽  
Author(s):  
R. ZARROUKI ◽  
Z. SAKHI ◽  
M. BENNAI
Keyword(s):  
High Energy ◽  
Observational Constraints ◽  
Type Ii ◽  
Energy Limit ◽  
High Energy Limit ◽  
Inflation Model ◽  
Slow Roll ◽  
Braneworld Model ◽  
Perturbation Spectrum ◽  
Good Agreement

We study a new inflation potential in the framework of the Randall–Sundrum type II braneworld model. Using the technic developed in Ref. 1, we consider both a monomial and a new inflation potentials and apply the slow-roll approximation in high energy limit, to derive analytical expression of relevant perturbation spectrum. We show that for some values of the parameter n in the potential [Formula: see text] we obtain a perturbation spectrum which gives a good agreement with the recent WMAP5 observations.

TACHYONIC BRANEWORLD INFLATION AND OBSERVATIONS

2013 ◽  
Vol 28 (15) ◽  
pp. 1350062 ◽  
Author(s):  
R. ZARROUKI ◽  
Z. SAKHI ◽  
M. BENNAI
Keyword(s):  
Power Law ◽  
High Energy ◽  
Inverse Power ◽  
Tachyonic Field ◽  
Astronomical Observations ◽  
Slow Roll ◽  
Inverse Power Law ◽  
Braneworld Model ◽  
Braneworld Inflation

We study various tachyonic inflationary spectrum perturbations in the context of the Randall–Sundrum type-2 braneworld model [L. Randall and R. Sundrum, Phys. Rev. Lett.83, 3370 (1999); Phys. Rev. Lett.83, 4690 (1999)]. We consider, in particular, the inverse power law potential [Formula: see text] of the tachyonic field in the high-energy and slow-roll approximations using the recent astronomical observations.

scholarly journals Light of Planck-2015 on Noncanonical Inflation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kh. Saaidi ◽  
A. Mohammadi ◽  
T. Golanbari
Keyword(s):  
Scalar Field ◽  
Observational Data ◽  
Power Law ◽  
Hubble Parameter ◽  
Field Model ◽  
Kinetic Term ◽  
Inflationary Scenario ◽  
Slow Roll ◽  
Power Law Function ◽  
Free Parameters

Slow-roll inflationary scenario is considered in noncanonical scalar field model supposing a power-law function for kinetic term and using two formalisms. In the first approach, the potential is picked out as a power-law function, that is, the most common approach in studying inflation. Hamilton-Jacobi approach is selected as the second formalism, so that the Hubble parameter is introduced as a function of scalar field instead of the potential. Employing the last observational data, the free parameters of the model are constrained, and the predicted form of the potential and attractor behavior of the model are studied in detail.

Inflationary cosmology for f(R, ϕ) models with different potentials

2017 ◽  
Vol 95 (11) ◽  
pp. 1074-1085 ◽  
Author(s):  
M. Zubair ◽  
Farzana Kousar
Keyword(s):  
Scalar Field ◽  
Equation Of State ◽  
Energy Density ◽  
Cosmological Constant ◽  
Observational Data ◽  
Power Law ◽  
Early Time ◽  
Inflationary Cosmology ◽  
Effective Equation ◽  
Slow Roll

We examine inflation in [Formula: see text] theory, where a scalar field is coupled to gravity. We have constructed [Formula: see text] models using exponential and power law potentials and study inflation for these models, which can support the early-time acceleration with a useful cosmological constant at high curvature. We have calculated the slow-roll parameters, scalar-to-tensor ratio, and spectral index for these models and analyzed them graphically to check the viability according to recent observational data. We have also presented the evolution of effective equation of state and energy density.

scholarly journals DYNAMICS AND HOLOGRAPHIC DISCRETENESS OF TACHYONIC INFLATION

2003 ◽  
Vol 18 (01) ◽  
pp. 31-39 ◽  
Author(s):  
BIN WANG ◽  
ELCIO ABDALLA ◽  
RU-KENG SU
Keyword(s):  
Power Law ◽  
Evolution Equations ◽  
Inverse Power ◽  
Brane Cosmology ◽  
Slow Roll ◽  
Inverse Power Law ◽  
Entropy Bound

We consider issues related to tachyonic inflation with inverse-power-law potential. We find the solution of the evolution equations in the slow-roll limit in FRW as well as in the brane cosmology. Using the holographic entropy bound, we estimate the quantum-gravitational discreteness of tachyonic inflation perturbations.

scholarly journals Hubble inflation in Randall–Sundrum type II model

2020 ◽  
Vol 29 (06) ◽  
pp. 2050037
Author(s):  
Habib Abedi ◽  
Amir M. Abbassi ◽  
Sebastian Bahamonde
Keyword(s):  
Field Model ◽  
High Energy ◽  
Expansion Rate ◽  
Type Ii ◽  
Flow Equations ◽  
Hubble Expansion ◽  
Jacobi Formalism ◽  
Inflationary Parameters ◽  
High Energy Regime ◽  
Model Features

We study a braneworld Randall–Sundrum type II (RSII) model using the Hamilton–Jacobi formalism. We extend the standard inflationary parameters and the flow equations for this braneworld scenario. We investigate the conditions that reduce the infinite number of flow equations into a finite number and confirm that by considering one of the inflationary parameters that vanishes, the Hubble expansion rate gets a polynomial form in both General Relativity (GR) and in the high-energy regime of RSII. We also show that if one sets this inflationary parameter to a constant value, the model features a nonpolynomial form of the Hubble expansion rate. The form of the Hubble parameter in this case is different in GR and RSII. Next, we consider a single-scalar field model with a Hubble expansion rate behaving as [Formula: see text] and show that compared to GR, the RSII model has a smaller tensor-to-scalar ratio and larger spectral index for [Formula: see text]. Therefore, RSII model leads to better predictions than GR.

Inflationary constraints in teleparallel gravity theory

2020 ◽  
pp. 2150027
Author(s):  
Shambel Sahlu ◽  
Joseph Ntahompagaze ◽  
Amare Abebe ◽  
David F. Mota
Keyword(s):  
Observational Data ◽  
Spectral Index ◽  
Power Law ◽  
Teleparallel Gravity ◽  
Gravity Models ◽  
Index Formula ◽  
Scalar Tensor Theory ◽  
Tensor Theory ◽  
Slow Roll ◽  
Inflationary Parameters

In this work, the cosmological inflationary parameters in the correspondence of teleparallel gravity for the scalar–tensor theory are investigated. After the review of [Formula: see text] and [Formula: see text] gravity cosmology, we use the slow-roll approximations to study the behavior of the inflationary parameters namely the spectral index [Formula: see text] and tensor-to-scalar ratio [Formula: see text], and a comparison with observational data for different paradigmatic [Formula: see text] gravity models such as exponential, Linder and power-law models is considered. We also consider the boundary term [Formula: see text] associated with these three models. The obtained behavior of the parameters under consideration shows that it is possible to constrain [Formula: see text] and [Formula: see text] models based on observational data.

scholarly journals NMC and the Fine-Tuning Problem on the Brane

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
A. Safsafi ◽  
M. Bennai
Keyword(s):  
Coupling Parameter ◽  
Higgs Field ◽  
High Energy ◽  
Fine Tuning ◽  
Type Ii ◽  
Coupling Constant ◽  
Energy Limit ◽  
Transformation Techniques ◽  
Slow Roll ◽  
Braneworld Model

We propose a new solution to the fine-tuning problem related to coupling constantλof the potential. We study a quartic potential of the formλϕ4in the framework of the Randall-Sundrum type II braneworld model in the presence of a Higgs field which interacts nonminimally with gravity via a possible interaction term of the form-(ξ/2)ϕ2R. Using the conformal transformation techniques, the slow-roll parameters in high energy limit are reformulated in the case of a nonminimally coupled scalar field. We show that, for some value of a coupling parameterξand brane tensionT, we can eliminate the fine-tuning problem. Finally, we present graphically the solutions of several values of the free parameters of the model.

Inverse Power Law Behavior in a Memory Scanning Experiment

2006 ◽  
Author(s):  
Gerardo Ramirez ◽  
Sonia Perez ◽  
John G. Holden
Keyword(s):  
Power Law ◽  
Inverse Power ◽  
Memory Scanning ◽  
Inverse Power Law
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