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.

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.

scholarly journals On Chaplygin Gas Braneworld Inflation with Monomial Potential

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
A. Safsafi ◽  
I. Khay ◽  
F. Salamate ◽  
H. Chakir ◽  
M. Bennai
Keyword(s):  
High Energy ◽  
Chaplygin Gas ◽  
Type Ii ◽  
Energy Limit ◽  
Generalized Chaplygin Gas ◽  
Planck Data ◽  
Central Value ◽  
Braneworld Model ◽  
Perturbation Parameters ◽  
Braneworld Inflation

We study the Chaplygin gas model as a candidate for inflation in the framework of the Randall-Sundrum type II braneworld model. We consider the original and generalized Chaplygin gas model in the presence of monomial potential. The inflationary spectrum perturbation parameters are reformulated and evaluated in the high-energy limit and we found that they depend on several parameters. We also showed that these perturbation parameters are widely compatible with the recent Planck data for a particular choice of the parameters space of the model. A suitable observational central value of ns≃0.965 is also obtained in the case of original and generalized Chaplygin gas.

scholarly journals F-TERM BRANEWORLD INFLATION IN LIGHT OF FIVE-YEAR WMAP OBSERVATIONS

2010 ◽  
Vol 25 (17) ◽  
pp. 3445-3451 ◽  
Author(s):  
A. BOUAOUDA ◽  
R. ZARROUKI ◽  
H. CHAKIR ◽  
M. BENNAI
Keyword(s):  
Scalar Potential ◽  
Fine Tuning ◽  
Type Ii ◽  
Brane Tension ◽  
Coupling Constant ◽  
Analytical Expression ◽  
Hybrid Inflation ◽  
Braneworld Model ◽  
Braneworld Inflation

We consider a supersymmetric hybrid inflation in the framework of the Randall–Sundrum type II braneworld model. We derive an analytical expression for the scalar potential and find that the F-term dominates the hybrid inflation process. We show that, for some value of brane tension, we can eliminate the fine-tuning problem related to coupling constant κ of the potential. We also calculate all known spectrum inflation parameters and show that observational bounds from WMAP5, BAO and SN observations are satisfied.

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.

Observational constraints on reheating in braneworld inflation

2019 ◽  
Vol 34 (27) ◽  
pp. 1950152
Author(s):  
Z. Sakhi ◽  
A. Safsafi ◽  
M. Ferricha-Alami ◽  
H. Chakir ◽  
M. Bennai
Keyword(s):  
Cosmological Parameters ◽  
High Energy ◽  
Observational Constraints ◽  
Brane Tension ◽  
Energy Limit ◽  
Polynomial Potential ◽  
High Energy Limit ◽  
Slow Roll ◽  
Braneworld Inflation ◽  
Best Fit

The reheating era after inflation is analyzed in the framework of the braneworld models. We study reheating by calculating the reheating temperature in a braneworld inflation for various cosmological parameters. The variation of reheating [Formula: see text]-folding number and reheating temperature were obtained and analyzed as function of a spectrum of perturbation for a polynomial potential [Formula: see text]. We have applied the slow-roll approximation in the high energy limit to constraint the parameter potentials by confronting our results to recent Planck 2018 observations. We have shown that in general the best values of the predicted reheating temperature is of the order [Formula: see text] GeV, with a brane tension [Formula: see text] GeV4. We have also shown that the polynomial potential in the case [Formula: see text] provides the best fit results with recent observational constraints.

scholarly journals Tachyon-polytropic inflation on the brane

Open Physics ◽  
2013 ◽  
Vol 11 (5) ◽  
Author(s):  
Mohammad Setare ◽  
Vahid Kamali
Keyword(s):  
Equation Of State ◽  
Cosmological Parameters ◽  
High Energy ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Inflationary Universe ◽  
Universe Model ◽  
Exponential Potential ◽  
Energy Limit ◽  
High Energy Limit ◽  
Slow Roll

AbstractWe consider the tachyon-brane inflationary universe model in the context of a polytropic gas equation of state. In slow-roll approximation, we discuss general conditions of this model. For exponential potential, in high-energy limit the characteristics of the model are presented. By using the seven-year Wilkinson Microwave Anisotropy Probe (WMAP7) observational data, we constrain the cosmological parameters of the model.

OBSERVATIONAL CONSTRAINTS ON D-TERM BRANEWORLD INFLATION

2012 ◽  
Vol 27 (36) ◽  
pp. 1250205 ◽  
Author(s):  
A. SAFSAFI ◽  
A. BOUAOUDA ◽  
H. CHAKIR ◽  
J. INCHAOUH ◽  
M. BENNAI
Keyword(s):  
Scalar Potential ◽  
Fine Tuning ◽  
Observational Constraints ◽  
Observation Data ◽  
Coupling Constant ◽  
Analytical Expression ◽  
Hybrid Inflation ◽  
Braneworld Model ◽  
Braneworld Inflation

We consider a supersymmetric hybrid inflation in the framework of the Randall–Sundrum type-2 braneworld model. We derive an analytical expression for the effective scalar potential and find that the D-term dominates hybrid inflation process. We show that we can eliminate partially the fine tuning problem related to coupling constant λ of the potential and calculate the value of FI-term ξ according to recent WMAP7 observation data. We show also that some inflationary spectrum parameters, in particular, the ratio r and the running [Formula: see text] are widely consistent with WMAP7, BAO and H0 data.

scholarly journals $$\alpha $$-attractor from superconformal E-models in brane inflation

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Mudassar Sabir ◽  
Waqas Ahmed ◽  
Yungui Gong ◽  
Yizhou Lu
Keyword(s):  
Friedmann Equation ◽  
High Energy ◽  
Model Parameters ◽  
Quadratic Term ◽  
Additional Parameter ◽  
Energy Limit ◽  
Brane Inflation ◽  
Slow Roll ◽  
Scalar Spectral Index ◽  
Braneworld Inflation

AbstractIn the large extra dimensional braneworld inflation, Friedmann equation is modified to include a quadratic term in energy density with an additional parameter $$\lambda $$λ called brane tension in addition to the usual linear term. The high energy brane corrections modify the slow-roll parameters and affect the behaviour of inflation. We analyse the superconformal inflation for E-models and find that there exist $$\alpha $$α-attractors in brane inflation. The predictions for the scalar spectral index $$n_s$$ns and the tensor-to-scalar ratio r are computed numerically, and approximate analytic formulas in the high energy limit have been given for the observable $$n_s$$ns and r. The constraints on the model parameters are obtained by using Planck 2018 and BICEP2 observational data.

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 Unitarity violation and the geometry of Higgs EFTs

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Timothy Cohen ◽  
Nathaniel Craig ◽  
Xiaochuan Lu ◽  
Dave Sutherland
Keyword(s):  
Standard Model ◽  
Higgs Field ◽  
Higgs Sector ◽  
High Energy ◽  
Effective Field ◽  
Energy Limit ◽  
Geometric Invariants ◽  
Energy Behavior ◽  
The Standard Model ◽  
Derivatives Of

Abstract We derive the scale of unitarity violation from the geometry of Effective Field Theory (EFT) extensions of the Standard Model Higgs sector. The high-energy behavior of amplitudes with more than four scalar legs depends on derivatives of geometric invariants with respect to the physical Higgs field h, such that higher-point amplitudes begin to reconstruct the scalar manifold away from our vacuum. In theories whose low-energy limit can be described by the Higgs EFT (HEFT) but not the Standard Model EFT (SMEFT), non-analyticities in the vicinity of our vacuum limit the radius of convergence of geometric invariants, leading to unitarity violation at energies below 4πv. Our results unify approaches to the HEFT/SMEFT dichotomy based on unitarity, analyticity, and geometry, and more broadly illustrate the sense in which observables probe the geometry of an EFT. Along the way, we provide novel basis-independent results for Goldstone/Higgs boson scattering amplitudes expressed in terms of geometric covariant quantities.

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