Aspectos de estruturas tipo-kink e modelos de branas espessas

Abstract

In this thesis, we discuss several features of kinklike structures in both at and curved space. Initially, we review some general aspects about classical eld theories described by scalar elds that support localized structures. We investigate these theories in the two-dimensional at space-time and also in the braneworld scenario with a single extra dimension of in nite extension. After that, we discussed our contributions to the subject. First, using the deformation method, we show how to obtain di erent models of scalar eld theories that have the same stability potential. From systems that interact polynomially or hyperbolically, we use a deformation function that allowed us to build other theories with the characteristic of developing the same stability potentials. This deformation function leads to smooth potentials according to a speci c choice of a single parameter. We also show that for models with asymmetric topological sectors, the appearance of a new stability potential is possible. Finally, we present new models of thick branes in a system with two scalar elds that interact with each other in a very speci c way. The mechanism is new, capable of generating kinklike con gurations that engender important modi cations in the energy density of the system. Under appropriate considerations, we show that the mechanism also works to built models with an asymmetric pro le