arXiv subjects

A. S. Lobão

Publications and source records attributed to A. S. Lobão.

3 recordsLinked to original sources

arXiv2025

Kinks in generalized scalar field models and their scattering properties

This work investigates kink solutions in one-dimensional scalar field theories. We begin with a review of the formalism used to obtain these solutions, presenting the BPS formalism and linear stability analysis. Next, we explore new models involving real scalar fields, generated by distinct potentials, with a focus on the topological structures responsible for the formation of kinks. Finally, we study collisions between the solutions obtained in two distinct models, analyzing their dynamic implications.

hep-th↗

arXiv2024

Hybrid branes from split kinks

In this work, we investigate braneworld models generated by scalar fields in which one field has a split kink profile, in which a kink separates into two kinklike configurations. Our analysis covers models with two and three fields, examining the behavior of the most important quantities associated with the brane, such as the warp factor and the stability of the corresponding gravity sector. The results show that the brane is stable and supports a hybrid character, behaving as a thin and thick configuration.

hep-th↗

arXiv2023

Scalar-tensor representation to $f(R,T)-$brane with Gauss-Bonnet gravity

In this paper, we generalize the analysis of the $f(R,T)-$brane via the inclusion of a term proportional to the Gauss-Bonnet invariant. We consider an action of the form $F(R,G,T)=f(R,T)+αG$, where $T$ is the trace of the stress-energy tensor, $R$ is the Ricci scalar, and $α$ is a real parameter that controls the contribution of the Gauss-Bonnet invariant $G$. We introduce the first-order formalism to obtain solutions for the source field of the brane in the special case where $f(R,T)=R+βT$ and illustrate its procedure with an application to the sine-Gordon model. We also investigate the general case of the $f(R,T)-$brane via the use of the scalar-tensor formalism, where we also use the first-order formalism to obtain solutions. Finally, we investigate the linear stability of the brane under tensor perturbations of the the modified Einstein's field equations. Our results indicate that the Gauss-Bonnet term may induce qualitatively different behaviors of the quantities on the brane, provided that its contribution is large enough.

gr-qc↗