Refinements of the Weyl Pure Geometrical Thick Branes From Information‐Entropic Measure

This work aims to analyse the so‐called configurational entropy in the Weyl pure geometrical thick brane model. The Weyl structure plays a prominent role in the brane thickness of this model. We find a set of parameters associated to the brane width where the configurational entropy exhibits critical points. The information‐theoretical measure sets bounds into parameter of Weyl pure geometrical brane model. In addition, we also argue that a similar approach can be useful to analyze the corrections to Newtonian and Coulombian potentials in Weyl scenarios.     

Kalb-Ramond field localization on a thick de Sitter brane

In this paper, we explore the localization condition of Kalb-Ramond(KR) tensorial gauge field on a thick de Sitter(dS) brane. Following the localization mechanism in the work by Chumbes et al(2012 Phys. Rev. D 85 085003), we analyze the localization of KR tensorial gauge field on a non-flat three-brane. We propose three kinds of coupling methods and two of them support the localization of zero mode. In addition, there exist resonant Kaluza-Klein modes on the thick dS brane. The effects of three parameters on the localization and the resonant mode for the KR field are also discussed.     

The Dynamics of Chung-Freese Braneworld

It is shown that the ansatz of Chung-Freese models a new braneworld, and while superluminal, this braneworld does not suffer from the pathologies of other FTL methods. It is also shown that our universe is a trapped surface inside a universe with large extra dimensions, and in order to preserve compatibility with the Standard Model (SM), we present two trapping mechanisms that keeps SM fields inside our brane. For the Chung-Freese braneworld we develop a similar formalism to Morris domain walls, and we present our universe as a low level state in a potential well with the bulk in the highest levels of potential. Finally, we show that the Israel condition can also act as a trapping mechanism for SM fields inside the brane. Our model uses the idea that fermions are allowed to escape to the bulk inspired by the work of Havoudiasl-Hewett-Rizzo [2].     

Inflation with hyperbolic potential in the braneworld model

In this paper we study inflationary dynamics with a scalar field in an inverse coshyperbolic potential in the braneworld model. We note that a sufficient inflation may be obtained with the potential considering slow-roll approximation in the high energy limit. We determine the minimum values of the initial inflaton field required to obtain sufficient inflation and also determine the relevant inflationary parameters. The numerical values of spectral index of the scalar perturbation spectrum are determined by varying the number of e-foldings for different initial values of the inflaton field. The result obtained here is in good agreement with the current observational limits.      

de Sitter branes with a bulk scalar

We propose new brane world models arising from a scalar field in the bulk. In these examples, the induced on-brane line element is de Sitter (or anti de Sitter) and the bulk (five dimensional) Einstein equations can be exactly solved to obtain warped spacetimes. The solutions thus derived are single and two-brane models—one with thin branes while the other one of the thick variety. The field profiles and the potentials are obtained and analysed for each case. We note that for the thick brane scenario the field profile resembles a kink, whereas for one or more thin branes, it is finite and bounded in the domain of the extra dimension. We have also addressed the localisation of gravity and other matter fields on the brane for these braneworld models.     

Inflationary dynamics in the braneworld scenarios

We analyze the attractor behaviour of the inflation field in braneworld scenarios using the Hamilton-Jacobi formalism, where the Friedmann equation has the form of H2 = ρ + ε(2ρ0ρ)~(1/2) or H2 = ρ + ερ2/2σ , with ε = ±1. We find that in all models the linear homogeneous perturbation can decay exponentially as the scalar field rolls down its potential. However, in the case of a -ρ2 correction to the standard cosmology with ρ σ , the existence of an attractor solution requires (σρ)/φ2 1. Our results show that the perturbation decays more quickly in models with positive-energy correction than in the standard cosmology, which is opposite to the case of negative-energy correction. Thus, the positive-energy modification rather than the negative one can assist the inflation and widen the range of initial conditions.     

D-term Chaotic Braneworld in Supergravity Constrained by WMAP9 Data

We study a supergravity D-term chaotic inflationary model, in the context of the braneworld scenario, in particular we consider the Randal1-Sundrum model type 2. Using the latest release from the combination of WMAP9, eCMB, BAO, and Ho, we show that the inflation observables depend only on the number ore-folds N. We also derive all known spectrum inflationary parameters, which are widely consistent with WMAP9 data for a particular choice of values N specially for the scalar spectral index ns and the ratio r. However, the running of the scalar spectral index dns/dlnk is now excluded from the range given by the latest observational measurements.