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D. A. Ferreira

Publications and source records attributed to D. A. Ferreira.

6 recordsLinked to original sources

Internal structure of cuscuton Bloch brane

This work deals with thick branes in bulk with a single extra dimension modeled by a two-field configuration. We first consider the inclusion of the cuscuton to also control the dynamics of one of the fields and investigate how it contributes to change the internal structure of the configuration in two distinct situations, with the standard and the asymmetric Bloch brane. The results show that the branes get a rich internal structure, with the geometry presenting a novel behavior which is also governed by the parameter that controls the strength of the cuscuton term. We also study the case where the dynamics of one of the two fields is only described by the cuscuton. All the models support analytical solutions which are stable against fluctuations in the metric, and the main results unveil significant modifications in the warp factor and energy density of the branes.

hep-th↗

Symmetric and asymmetric thick brane structures

This work deals with the presence of thick branes in a model with two source scalar fields that interact with one another in a very specific way. The model is new, capable of generating kinklike configurations that engender important modifications in the energy density of the system, inducing the presence of symmetric and asymmetric structures inside the brane.

hep-th↗

First order formalism for thick branes in modified gravity with Lagrange multiplier

This work discuss the construction of braneworld solutions in modified gravity with Lagrange multipliers. We examine the general aspects of the model and present a first order formalism that help us to find analytic solutions of the equations of motion. We also investigate some explicit models, analyse linear stability of the metric and comment on how to relate models investigated in other works to the ones examined in the present study.

hep-th↗

New results on asymmetric thick branes

This work deals with the presence and stability of thick brane solutions in the warped five dimensional braneworld scenario with a single extra spatial dimension of infinite extent. We combine two distinct procedures that give rise to new possibilities, allowing that we describe models of asymmetric thick branes, with the asymmetry being controlled by a single real parameter. We illustrate the main results with some distinct models, which show that the method works for both standard and generalized models, and the solutions are gravitationally stable against small perturbations of the metric.

hep-th↗

Novel results for kinklike structures and their connections to quantum mechanics

In this work we use the deformation procedure and explore the route to obtain distinct field theory models that present similar stability potentials. Starting from systems that interact polynomially or hyperbolically, we use a deformation function which allows to construct other theories having the feature of giving rise to the same stability potentials. Such deformation function leads to smooth potentials according to a specific choice of a single parameter. Among the results, one shows that for models with asymmetric topological sectors, the appearance of a new stability potential is also possible.

hep-th↗

Building analytical three-field cosmological models

A difficult task to deal with is the analytical treatment of models composed by three real scalar fields, once their equations of motion are in general coupled and hard to be integrated. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called "extension method". The fundamental idea of the procedure is to combine three one-field systems in a non-trivial way, to construct an effective three scalar field model. An interesting scenario where the method can be implemented is within inflationary models, where the Einstein-Hilbert Lagrangian is coupled with the scalar field Lagrangian. We exemplify how a new model constructed from our method can lead to non-trivial behaviors for cosmological parameters.

gr-qc↗