arXiv subjects

F. C. E. Lima

Publications and source records attributed to F. C. E. Lima.

At least 19 recordsLinked to original sources

arXiv2026

Tensor resonances in teleparallel Gauss-Bonnet branes

We construct an analytical thick-brane solution in linear teleparallel Gauss-Bonnet gravity using a first-order formalism generated by a sine-Gordon superpotential. The resulting asymptotically $\mathrm{AdS}_5$ configurations exhibit brane splitting controlled by the dimensionless parameter $q=4αk^2$. An analytical splitting condition is derived and combined with tensor-stability requirements to identify the physically viable parameter region. We show that the tensor spectrum is free of tachyonic instabilities and supports a normalizable graviton zero mode. The massive sector exhibits odd-parity gravitational resonances whose quasi-localization is significantly enhanced near the stability boundary. Our results establish a direct link between brane splitting, tensor stability, and gravitational resonances in teleparallel Gauss-Bonnet braneworlds.

hep-th↗

arXiv2026

Geodesics and Thermodynamics of a Schwarzschild Black Hole with Hernquist Dark Matter

In this work, we investigate the physical and geometrical properties of a Schwarzschild black hole (BH) immersed in a Hernquist dark matter halo. To accomplish our purpose, one builds the BH metric by incorporating the Hernquist dark matter profile into the Schwarzschild geometry. In addition, we verify the null geodesic solutions and the Halo effect on photon dynamics. Within this framework, one examines the corresponding light trajectories to determine the deformation of photon paths generated by the dark matter distribution. Furthermore, the thermodynamic properties of the system are studied by deriving expressions for the black hole mass, the horizon condition, the Hawking temperature, the entropy, the Gibbs free energy, and the heat capacity. Our results show that the dark matter halo modifies the thermal structure and stability conditions of the black hole configuration. Finally, we investigate the scalar perturbations to examine the influence of the Hernquist halo on the dynamical propagation of scalar fields in the BH background. In this framework, the results obtained demonstrate that the dark matter parameters yield nontrivial corrections to the optical, thermodynamic, and perturbative properties of the Schwarzschild black hole, producing deviations from the standard vacuum solution.

gr-qc↗

arXiv2026

BPS lumps in the Nonminimal $CP^1$ Maxwell-Chern-Simons Model

We investigate self-dual radially symmetric configurations in the $CP^1$ model coupled to a Maxwell and Chern-Simons (CS) gauge fields through nonminimal interactions. Starting from the nonlinear $O(3)$-sigma model, we explicitly construct its classical mapping to the $CP^1$ formulation, highlighting the emergence of a local $U(1)$ gauge symmetry intrinsically associated with the Fubini-Study geometry of the target space. In the static regime, the combined effects of the Chern-Simons term and the Pauli-like nonminimal coupling modify the effective gauge connection, render the electric sector unavoidable, and give rise to magnetized and electrically polarized BPS lump configurations. By implementing the Bogomolnyi procedure, we determine the self-interaction potential required for self-duality and derive the corresponding BPS equations. We show that the magnetic flux remains quantized and is completely fixed by the asymptotic behavior of the gauge field, even in the presence of the Chern-Simons and nonminimal couplings. A detailed asymptotic analysis further reveals that finite-energy solutions necessarily correspond to lump-like configurations in which the $CP^1$ scalar field vanishes at spatial infinity. Numerical solutions of the BPS equations confirm that the resulting configurations are regular, spatially localized, and free of singularities, exhibiting confined magnetic flux together with a nontrivial localized electric field. These results show that the generalized $CP^1$-Maxwell-CS model supports self-dual solitons whose internal structure is rigidly governed by the target-space geometry rather than by spontaneous symmetry breaking.

hep-th↗

arXiv2026

Magnetized vortex in three-dimensional $\mathrm{f(R)}$ gravity

Modified Gravity Theories (MGTs) are extensions of General Relativity (GR) in its standard formulation. Therefore, within this framework, we will investigate a system composed of a black hole (BH) surrounded by Maxwell-Higgs vortices, forming the BH-vortex system. In the case of linear $f(R)$ gravity is adopted showing the existence of a three-dimensional ring-like BH-vortex system with quantized magnetic flux. Within this system, one notes the BH at $r=0$ and its event horizon at $r= r_0$, while the magnetic vortices are at $r \in (r_0, \infty)$. A remarkable result is the constancy of the Bekenstein-Hawking temperature ($T_H$), regardless of MGTs and vortex parameters. This invariance of $T_H$ suggests that the BH-vortex system reaches thermodynamic stability. Unlike the standard theory of Maxwell-Higgs vortices in flat spacetime, in $f(R)$ gravity, the vortices suffer the influence of the BH's event horizon. This interaction induces perturbations in the magnetic vortex profile, forming cosmological ring-like magnetic structures.

gr-qc↗

arXiv2026

Scalaron excitation by topological vortices in quadratic $f(R)$ gravity on a BTZ black hole background

In three spacetime dimensions, pure Einstein gravity admits no local propagating degrees of freedom, yet nontrivial gravitational backgrounds such as the BTZ black hole provide a natural arena to probe dynamical extensions of the theory. In quadratic $f(R)$ gravity the Ricci scalar becomes a propagating degree of freedom - the scalaron. We investigate how localized Maxwell-Higgs vortices excite this scalar mode in a static BTZ black-hole background. Working in the perturbative regime $α\ll \ell^2$, the trace equation reduces to a massive Klein-Gordon equation for the curvature scalar sourced by the trace of the vortex energy-momentum tensor. Using the Sturm-Liouville structure of the radial operator, we construct the corresponding Green function and obtain the curvature profile generated by an arbitrary localized source. The induced excitation exhibits a universal asymptotic decay $R(r) \sim r^{-(1+ν)}$, independent of the detailed vortex structure. The scalar excitation is linearly stable, carries finite energy, and produces parametrically suppressed backreaction, ensuring the smooth recovery of the Einstein limit. These results provide a concrete realization of how higher-curvature corrections activate the unique local gravitational degree of freedom in three dimensions and how localized sources excite this scalar mode in black-hole spacetimes.

gr-qc↗

arXiv2026

BPS vortex from nonpolynomial scalar QED in a $\mathds{C}\mathrm{P}^1$-Maxwell theory

We investigate a generalized gauged $\mathds{C}\mathrm{P}^1$-Maxwell theory in which the electromagnetic sector acquires a field-dependent magnetic permeability generated dynamically through fermionic vacuum polarization. Starting from the gauged $\mathds{C}\mathrm{P}^1$-sigma model, whose dynamics occurs on a curved target space endowed with the Fubini-Study metric, we show that integrating out a Dirac fermion with effective mass induces, at one loop, a non-polynomial magnetic permeability, which after dimensional reduction to $(2+1)$-dimensions yields an effective Maxwell sector takes the form of a logarithmic magnetic permeability. Within this framework, one builds a generalized $\mathds{C}\mathrm{P}^1$-Maxwell model by admitting Bogomol'nyi-Prasad-Sommerfield (BPS) configurations. Taking this into account, we solved the self-dual equations that describe vortex-like solutions with quantized magnetic flux. Furthermore, one highlights the interactions between the target-space geometry and the induced permeability.

hep-th↗

arXiv2025

Soft breaking of the $\mathbb{Z}_2$ symmetry in the $ϕ^4$ theory

We consider a two-dimensional scalar field theory that modifies the standard $ϕ^4$ model by introducing a smooth breaking of translational invariance through a hyperbolic generalizing function. This function explicitly breaks the $\mathbb{Z}_2$ symmetry; however, it also introduces a mechanism capable of generating new energy minima (vacua) and of localizing or delocalizing field fluctuations around these vacua. Thus, this mechanism enables the continuous transformation of the kink/antikink-like configurations into compacted asymmetric double-kink/antikink structures. Accordingly, this transformation gives rise to new classes of configurations resembling asymmetric non-topological solitons, characterized by a soft breaking of the $\mathbb{Z}_2$ symmetry. These findings are particularly compelling, as they are consistent with results describing Su-Schrieffer-Heeger (SSH) domain walls in dimerized polymer systems.

hep-th↗

arXiv2025

Geometrically expanding the BPS vortex of a non-canonical multi-field theory

Considering a non-canonical multi-field theory, we propose a mechanism of geometric expansion for Abrikosov-Nielsen-Olesen (ANO) vortices. One builds the general setup adopting a non-canonical O(3)-sigma model, non-minimally coupled through an anomalous magnetic dipole interaction to a gauge and real scalar field. By embracing a hyperbolic non-canonical extension, one finds that self-dual vortex configurations undergo geometric expansion, deforming ANO-like vortices into disk-like structures, mitigating their energy, and generating concentric energy rings around the core. Furthermore, these vortices exhibit quantized magnetic flux and degenerate solutions. Finally, we highlight that the analyzed vortices carry energy below the corresponding magnetic flux while preserving a singularity at their origin.

hep-th↗

arXiv2025

Properties of a Majorana fermion ensemble with exciton-like mass

Considering the relativistic scenario, we dedicate our study to the relativistic quantum description of one-dimensional Majorana fermions. Thus, we focus on aspects related to exciton-like particles. Seeking to reach our purpose, one analyzes the relativistic quantum mechanical system characterized by an effective mass distribution. In this context, we adopt an exciton-like position-dependent mass without impurity, i.e., without electromagnetic interactions. From this perspective, one notes results of noteworthy interest as consequences of the theory adopted. For instance, we highlight that, even without interaction, exciton-like Majorana fermions manifest theoretically bound states. Also, we construct a Majorana fermion ensemble with effective mass immersed in a thermal reservoir. That allows for a thorough investigation of the thermodynamic properties of the system. Among the thermodynamic characteristics studied in the canonical ensemble, we focus on the Helmholtz free energy, mean energy, entropy, and heat capacity. The numerical results obtained for these thermodynamic properties corroborate the validity of the Dulong-Petit law for our system.

cond-mat.mes-hall↗

arXiv2025

Mitigating the information degradation in a massive Unruh-DeWitt theory

We investigated the influence of the massive scalar field on the information degradation concerning the Unruh-DeWitt (UDW) detectors. In this conjecture, we adopted a system with a finite and large interaction time. To accomplish our purpose, one examines the quantum coherence of a uniformly accelerated qubit and the probability of finding the detector in the ground state. In this framework, we consider a quantum interferometric circuit to obtain the probability, visibility, and coherence. Naturally, these measurements provide us with wave-like information. Besides, one modifies the circuit to describe the path distinguishability and the particle-like information. These results are promising, as they allow us to understand the influence of the Unruh effect on the wave-particle duality. Thus, our findings announce that the increase in the scalar field mass induces a decrease in information degradation. Finally, we noted that the information concerning the Unruh effect remains preserved when $m \geq Ω$. Therefore, the detector cannot absorb particles with mass equal to or greater than its energy gap. These results indicate that the scalar field mass is a protective factor against information degradation for systems under high acceleration conditions.

hep-th↗

arXiv2025

Asymmetric domain walls in modified $ϕ^{4}$ theory: Excitation spectra, scattering, and decay of bions

We consider a two-dimensional Lorentz-invariant field model with a $ϕ^{4}$ potential modified by a term that introduces asymmetries at the manifold space. In this framework, the model recovers its original symmetry only when $p=0$. The asymmetry introduced in the potential suggests that, even when one of the minima diverges asymptotically, kink/antikink-like configurations emerge in the theory, shifting the critical point of the energy density away from the center of the kink-like solutions. Hence, we note that the model supports asymmetrical kink/antikink-like topological solutions. Furthermore, an analysis of the excitation spectrum of these solutions revealed the absence of vibrational modes. Finally, we examine the dynamical solutions for different values of initial velocity by allowing us to verify the effects of asymmetries on the collision properties.

hep-th↗

arXiv2025

On the singular position-dependent mass

Revisiting the issue associated with Position-Dependent Mass (PDM), we reaffirm that the appropriate framework for addressing a generic PDM is the symmetrization proposed by BenDaniel and Duke. To accomplish this result adopts the effective mass Hamiltonian proposed by von Roos, corrected by a symmetrized kinematic term. After verifying the appropriate ordering to approach the PDM issue, one investigates a crystalline lattice with a defect described by a singular PDM. The singular mass profile proves intriguing as it yields an atom's cluster in the neighborhood of the singularity. Considering that a restoring force acts on the atoms, one notes that the confluent Heun function describes the quantum states. Furthermore, one highlights that when the effective mass distribution tends to a constant profile, we recover a system similar to the harmonic oscillator.

quant-ph↗

arXiv2024

Kinks and double-kinks in generalized $ϕ^{4}$-and $ϕ^{8}$-models

Examining the $ϕ^{4}$ and $ϕ^{8}$ models within a two-dimensional framework in the flat spacetime and embracing a theory with unconventional kinetic terms, one investigates the emergence of kinks/antikinks and double-kinks/antikinks. We devote our study to obtaining the field configurations with minimal energy, i.e., solutions possessing a Bogomol'nyi-Prasad-Sommerfield's bound. Next, to accomplish our goal, we adopt non-polynomial generalizing functions, namely, hyperbolic sine and cosine functions: the first produce BPS potentials exhibiting a minimum at $ϕ=0$, facilitating the emergence of genuine double-kink-type configurations. Conversely, the second promotes the rise of kink-type solutions.

hep-th↗

arXiv2024

On the asymmetric non-canonical braneworld in five dimensions

Revisiting Einstein's gravitational theory, we build a five-dimensional braneworld. Within this framework, one announces the appearance of symmetric and asymmetric domain walls. Furthermore, it examines the emergent four-dimensional gravity from a theory with non-canonical dynamics. Exploring the physical and mathematical aspects, e.g., brane's energy density and the Kaluza-Klein (KK) spectrum, one verifies that brane splitting is absent in the canonical and non-canonical theories. Additionally, we note the localization of the four-dimensional fluctuation projection on the 3-branes, which ensures the theory's stability. Thereby, one can conclude that the behavior of gravitational perturbations of the domain wall maintains a profile similar to a stable and non-localizable tower of massive modes. In contrast, within the brane core, the matter sector generates new barriers and potential wells, resulting in massive modes with approximately symmetric amplitudes. However, the non-canonical dynamics generate massive modes with asymmetric amplitudes far from the 3-brane.

gr-qc↗

arXiv2024

Effects of quantum fluctuations of the metric on a braneworld

Adopting the premise that the expected value of the quantum fluctuating metric is linear, i.e., $\langle g^{μν}\rangle=αg^{μν}$, we analyze the modified gravity theory induced by the Einstein-Hilbert action coupled to a matter field. This approach engenders the $f(R,T)$ gravity used to investigate the braneworld. In this scenario, considering a thick brane, the influence of metric fluctuations on brane dynamics is investigated. Consequently, one shows how the metric fluctuations influence the vacuum states. This influence has repercussions for modifying the brane energy and the asymptotic profile of the matter field. After noticing these modifications, we analyzed the most likely and stable structures from the matter field. One performs this analysis considering the theoretical measure of differential configurational entropy.

gr-qc↗

arXiv2024

Physical aspects of the deformation of $\mathbb{Z}_2$ kinks in a generalized $ϕ^4$ model

We study a generalized $ϕ^4$ model that gives rise to BPS kink/antikink configurations with compacton-like profiles. One observes that the positive parameter controlling the generalizing function promotes an infinity degenerescence of the BPS solutions. We then use the Differential Configurational Complexity technique to distinguish the degenerate configurations, which allows us to obtain the parameter values providing the most likely field profiles. Besides, the analysis of the excitation spectrum of the model shows the existence of translational and vibrational modes. Thus, the emergence of bound states of solitons (bions) and resonance phenomena is guaranteed when analyzing the scattering of kink/antikink structures. In this way, one notes that depending on the initial velocity, the collision can be inelastic or quasi-elastic, even in the case of compacton-like configurations.

hep-th↗

arXiv2023

Aspects of kink-like structures in 2D dilaton gravity

The topological structures that arise from two-dimensional models are relevant physically and the first step towards understanding more complex systems. In this work, one studies the kink-like solutions of the matter field that emerge in a two-dimensional dilaton gravity scenario. Considering this scenario, we examine the linear stability of the matter field and the translational mode. Due to the specific profile of the solutions found, a differential configurational complexity (DCC) analysis of the system was necessary to confirm the nature of the structures. Furthermore, we study the interforce and scattering process, considering a pair of kink-antikink-like solutions in a fixed time ($t=0$).

hep-th↗

arXiv2023

Topological solitons in the sigma-cuscuton model

Building a multi-field theory with canonical and non-canonical contributions, one studies the topological solitons of the O(3)-sigma model. We propose a model constituted by the O(3)-sigma field, the cuscuton-like neutral scalar field, and Maxwell's field. We investigate BPS properties considering a theory without interaction. One performs this study by adopting the first-order formalism in a model with contribution non-canonical. Thus, these contributions will preserve the spontaneous symmetry breaking of the system. Concurrently, a non-minimal coupling between the sigma and the Maxwell field is assumed. In this scenario, interesting results arise, i.e., one notes that the solitons have an internal structure and ring-like profile. Furthermore, one observes that the ring-like configurations that emerge are directly related to the contribution of the cuscuton-like term.

hep-th↗