arXiv subjects

C. dos Santos

Publications and source records attributed to C. dos Santos.

14 recordsLinked to original sources

arXiv2026

Dynamics of Biased Domain Walls: The Rocket Effect

We investigate the dynamics of domain walls in scalar field theories with degenerate vacua (i.e., vacua of equal energy density) in which the scalar field mass depends on the vacuum state. Using analytical arguments and numerical simulations, we show that this vacuum dependence of the scalar field mass renders the emission of scalar radiation from domain walls anisotropic, preferentially toward regions with smaller scalar field mass. We further show that the resulting recoil (rocket) effect biases the evolution of cosmological domain wall networks in favor of the lower-mass vacuum, thereby promoting network decay. We also demonstrate that the biased evolution of domain walls in theories with degenerate vacua, previously attributed to asymmetries of the potential barrier near the local maximum, is instead primarily controlled by the vacuum dependence of the scalar field mass. More generally, in theories with non-degenerate vacua, this recoil mechanism constitutes an additional source of dynamical bias that can either hasten or delay network decay relative to the standard expectation based solely on differences in vacuum energy density.

astro-ph.CO↗

arXiv2025

Geometrically constrained sine-Gordon field: BPS solitons and their collisions

We consider an enlarged $(1+1)$-dimensional model with two real scalar fields, $ϕ$ and $χ$ whose scalar potential $V(ϕ,χ)$ has a standard $χ^4$ sector and a sine-Gordon one for $ϕ$. These fields are coupled through a generalizing function $f(χ)$ that appears in the scalar potential and controls the nontrivial dynamics of $ϕ$. We minimize the effective energy via the implementation of the BPS technique. We then obtain the Bogomol'nyi bound for the energy and the first-order equations whose solutions saturate that bound. We solve these equations for a nontrivial $f(χ)$. As the result, BPS kinks with internal structures emerge. They exhibit a two-kink profile. i.e. an effect due to geometrical constrictions. We consider the linear stability of these new configurations. In this sense, we study the existence of internal modes that play an important role during the scattering process. We then investigate the kink-antikink collisions, and present the numerical results for the most interesting cases. We also comment about their most relevant features.

hep-th↗

arXiv2025

Sine-Gordon kink lattice

We consider an extended model with two real scalar fields, $ϕ(x,t)$ and $χ(x,t)$. The first sector is controlled by the sine-Gordon superpotential, while the second field is submitted to the $χ^4$ one. The fields mutually interact via a nontrivial coupling function $f(χ)$ that also changes the kinematics of $ϕ$. We briefly review the implementation of the Bogomol'nyi-Prasad-Sommerfield (BPS) prescription. We then solve the resulting BPS equations for two different interactions $f$. The first one leads to a single kink-kink configuration, while the second one gives rise to a inhomogeneous sine-Gordon kink lattice. We study the linear stability of these new solutions, focusing on their translational modes. We also explore how the strength of the mutual interaction affects the BPS profiles. In particular, we show that a homogeneous lattice with identical kinks is attained in the regime of extremely strong interactions.

hep-th↗

arXiv2019

First-order solitons with internal structures in an extended Maxwell-$CP(2)$ model

We study a Maxwell-$CP(2)$ model coupled to a real scalar field through a dielectric function multiplying the Maxwell term. In such a context, we look for first-order rotationally symmetric solitons by means of the Bogomol'nyi algorithm, i.e. by minimizing the total energy of the effective model. We perform our investigation by choosing an explicit form of the dielectric function. The numerical solutions show regular vortices whose shapes dramatically differ from their canonical counterparts. We can understood such differences as characterizing the existence of an internal structure.

hep-th↗

arXiv2015

Topological vortices in generalized Born-Infeld-Higgs electrodynamics

A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born-Infeld-Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via introduction of three non-negative functions depending only in the Higgs field, namely, $G(|ϕ|)$, $w(|ϕ|) $ and $V(|ϕ|)$. A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampere law. Such a constraint allows to minimize the system energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of topological vortex solutions in Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models such that a generalized version of Maxwell-Higgs electrodynamics is recovered in a certain limit of the theory.

hep-th↗

arXiv2014

Analytical BPS Maxwell-Higgs vortices

We have established a prescription for the calculation of analytical vortex solutions in the context of generalized Maxwell-Higgs models whose overall dynamics is controlled by two positive functions of the scalar field. We have also determined a natural constraint between these functions and the Higgs potential allowing the existence of axially symmetric Bogomol'nyi-Prasad-Sommerfield (BPS) solutions possessing finite energy. Furthermore, when the generalizing functions are chosen suitably, the nonstandard BPS equations can be solved exactly. We have studied some examples, comparing them with the usual Abrikosov-Nielsen-Olesen (ANO) solution. The overall conclusion is that the analytical self-dual vortices are well-behaved in all relevant sectors, strongly supporting the generalized models they belong themselves. In particular, our results mimic well-known properties of the usual (numerical) configurations, as localized energy density, while contributing to the understanding of topological solitons and their description by means of analytical methods.

hep-th↗

arXiv2014

BPS solitons in a Dirac-Born-Infeld action

We present several classes of solitons in ($1+1$)-dimensional models where the standard canonical kinetic term is replaced by a Dirac-Born-Infeld (DBI) one. These are static solutions with finite energy and different properties, namely, they can have compact support, or be kink or lump-like, according to the type of potential chosen, which depend on the DBI parameter $β$. Through a combination of numerical and analytical arguments, by which the equation of motion is seen as that corresponding to \emph{another} canonical model with a new $β$-dependent potential and a $β$-deformed energy density, we construct models in which increasing smoothly the DBI parameter both the compacton radius, the thickness of the kink and the width of the lump get modified until each soliton reaches its standard canonical shape as $β\rightarrow \infty$. In addition we present compacton solutions whose canonical counterparts are not compact.

hep-th↗

arXiv2013

Deformation method for generalized Abelian Higgs-Chern-Simons models

We present an extension of the deformation method applied to self-dual solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a model defined by a potential $V(| ϕ|)$ and a non-canonical kinetic term $ω(| ϕ|) | D_μϕ|^2$ whose analytical domain wall solutions are known, we show that this method allows to obtain an uncountable number of new analytical solutions of new models defined by other functions $\widetilde{V}$ and $\widetildeω$. We present some examples of deformation functions leading to new families of models and their associated analytic solutions.

hep-th↗

arXiv2013

Analytical self-dual solutions in a nonstandard Yang-Mills-Higgs scenario

We have found analytical self-dual solutions within the generalized Yang-Mills-Higgs model introduced in Phys. Rev. D 86, 085034 (2012). Such solutions are magnetic monopoles satisfying Bogomol'nyi-Prasad-Sommerfield (BPS) equations and usual finite energy boundary conditions. Moreover, the new solutions are classified in two different types according to their capability of recovering (or not) the usual 't Hooft--Polyakov monopole. Finally, we compare the profiles of the solutions we found with the standard ones, from which we comment about the main features exhibited by the new configurations.

hep-th↗

arXiv2012

Deforming solitons in generalized Abelian Higgs models

This work deals with several aspects of the extension to Abelian Higgs models of the deformation method originally developed for scalar field models. We present several examples allowing to transform self-dual solutions of different generalized Abelian Higgs models into scalar field models with or without a gauge field component. This is done through a parametrization of the soliton orbit in terms of the sine-Gordon static kink. We extend these ideas to a nonAbelian Higgs model.

hep-th↗

arXiv2012

BPS Solutions to a Generalized Maxwell-Higgs Model

We look for topological BPS solutions of an Abelian-Maxwell-Higgs theory endowed by non-standard kinetic terms to both gauge and scalar fields. Here, the non-usual dynamics are controlled by two positive functions, G(|ϕ|) and w(|ϕ|), which are related to the self-dual scalar potential V(|ϕ|) of the model by a fundamental constraint. The numerical results we found present interesting new features, and contribute to the development of the recent issue concerning the study of generalized models and their applications.

hep-th↗

arXiv2011

Generalized sine-Gordon solitons

In this paper we construct analytical self-dual soliton solutions in (1+1) dimensions for two families of models which can be seen as generalizations of the sine-Gordon system but where the kinetic term is non-canonical. For that purpose we use a projection method applied to the Sine-Gordon soliton. We focus our attention on the wall and lump-like soliton solutions of these k-field models. These solutions and their potentials reduce to those of the Klein-Gordon kink and the standard lump for the case of canonical kinetic term. As we increase the non-linearity on the kinetic term the corresponding potentials get modified and the nature of the soliton may change, in particular, undergoing a topology modification. The procedure constructed here is shown to be a sort of generalization of the deformation method for a specific class of k-field models.

hep-th↗

arXiv2010

Generalized self-dual Chern-Simons vortices

We search for vortices in a generalized Abelian Chern-Simons model with a nonstandard kinetic term. We illustrate our results, plotting and comparing several features of the vortex solution of the generalized model with those of the vortex solution found in the standard Chern-Simons model.

hep-th↗

arXiv2010

Compactlike kinks and vortices in generalized models

This work deals with the presence of topological defects in k-field models, where the dynamics is generalized to include higher order power in the kinetic term. We investigate kinks in (1,1) dimensions and vortices in (2,1) dimensions, focusing on some specific features of the solutions. In particular, we show how the kinks and vortices change to compactlike solutions, controlled by the parameter used to introduce the generalized models.

hep-th↗