arXiv subjects

M. J. Neves

Publications and source records attributed to M. J. Neves.

At least 19 recordsLinked to original sources

arXiv2026

Aspects of the quantization of non-linear electrodynamics in an uniform magnetic background

The canonical and path integral quantization for non-linear electrodynamics in the presence of an external electromagnetic (EM) field are proposed in this work. The EM background field is introduced expanding a general lagrangian of a generic non-linear electrodynamics around the background for small fluctuations of the propagating fields, where we consider up to the quadratic terms in the propagating fields. As consequence, we obtain an electrodynamics linearized by the presence of the external EM field. Thereby, we study the canonical quantization calculating the energy for the ground state of the linearized EM field in terms of an external magnetic field. The microcausality of the model also is discussed through the Pauli-Jordan function. We also define a generating functional for the linearized EM field, in which, in the Coulomb gauge, the Green function of the model is obtained, and we can construct the perturbative formalism like in standard quantum field theory (QFT). As application of the perturbation theory, the effective potential at one loop is calculated for the linearized EM field coupled to a complex scalar field. We apply the results in the case of the Modified Maxwell ED.

hep-th↗

arXiv2026

One-loop effective potential in Kalb-Ramond scalar electrodynamics

In this work, we study the effective potential at one loop for the Kalb-Ramond scalar electrodynamics. The model is based on a complex scalar field coupled to the electromagnetic field as usual, and also to the Kalb-Ramond field through the dual vector associated with the strength tensor of the $2$-form gauge field. There is an additional topological coupling of the electromagnetic field and the Kalb-Ramond field. The quantum corrections generated by the Kalb-Ramond sector are computed using dimensional regularization, and the ultraviolet divergences are removed by introducing the appropriate counterterms, leading to a finite renormalized effective potential. We find that the effective potential at one-loop generates terms of the form $\phi^6$, which is not present in the original bare Lagrangian. As a result, we introduced new counter terms to eliminate such divergences. The theory thus considered is not closed under renormalization.

hep-th↗

arXiv2026

Wave propagation and hybridization of plasmonic modes in Maxwell-Chern-Simons pseudo-electrodynamics

We investigate the propagation of classical plane waves and surface plasmon-polariton modes within the framework of pseudo-electrodynamics (PED) supplemented by a non-local Chern-Simons (CS) topological term. Starting from the dimensionally reduced action, we derive the decoupled second-order wave equations for the electromagnetic field, and for the gauge-potential. In vacuum, we show that the topological CS parameter works as a dynamical mass generator, modifying the strict transversality of plane waves, and introducing a distinct energy \textit{gap} in the dispersion relation. Considering a planar conducting medium that satisfies the Ohm law, the topological mass induces a novel hybridization mechanism between the Transverse Electric (TE), and Transverse Magnetic (TM) modes, a feature entirely absent in the conventional planar plasmonics. We analyze the asymptotic limits of this system, obtaining the exact real solutions in the lossless reactive Drude regime, and deriving the complex refractive index through a quasi-local approximation in the dissipative regime.

physics.optics↗

arXiv2026

Conservation laws in classical Poisson field theories

Poisson electrodynamics is the semiclassical limit of the full $U(1)$ non-commutative gauge theory, also known in recent literature as Poisson gauge theory. Two consolidated models for the theory studied in recent years, with a specific choice of non-commutative parameter, Lie-Poisson structures and constant ones, the later also known as the canonical, or Heisenberg case. In this paper, we present the theory considering the new building blocks related to symmetries and conservation laws, as a first step toward understanding the necessary mathematical tools to uncover some of the unknown pieces. We consider non-interacting examples of pure gauge fields, and classical Poisson field theories, related with real and complex scalar fields, as well as fermionic fields, using a constant spacelike deformation parameter. We show that the non-relativistic limit for the non-commutative Dirac equation introduces an orbital Zeeman coupling term for the fermionic fields, and the energy shift in the first excited state depends exclusively on the non-commutative parameter.

hep-th↗

arXiv2026

Two-Component Dark Matter in the Type-I 2HDM

We investigate a two-component dark matter scenario in the type-I two-Higgs-doublet model. The dark sector contains a real scalar $s$ and a Dirac fermion $\chi$, whose stability is ensured by a $Z_4$ symmetry together with kinematic conditions. The scalar interacts with the visible sector through Higgs-portal couplings, while the fermion interacts with the scalar via Yukawa interactions. In this framework, we analyze the thermal freeze-out production of both candidates, accounting for annihilation, conversion, and semi-annihilation processes. A comprehensive scan over the multidimensional parameter space is performed in terms of physical masses, mixing angles, and portal couplings, imposing theoretical requirements such as perturbativity and vacuum stability. We confront the model with current experimental constraints, including the observed relic abundance, invisible Higgs decays, direct detection limits on spin-independent scattering cross sections, and electroweak precision observables. We find that viable regions of parameter space can satisfy all dark matter constraints, but collider bounds strongly constrain the scalar sector, narrowing the allowed regions and creating tension with those favored by dark matter phenomenology, particularly in the sub-TeV mass regime.

hep-ph↗

arXiv2026

Kerr rotation signature of nonlinear Maxwell electrodynamics under a uniform electromagnetic background

Nonlinear electrodynamics naturally arises in quantum field theory, where the electromagnetic vacuum behaves as an effective nonlinear optical medium, leading to phenomena such as vacuum birefringence and dichroism. Among the recently proposed models, modified Maxwell electrodynamics (ModMax) stands out as a conformally invariant nonlinear extension of Maxwell theory that preserves the fundamental symmetries of classical electrodynamics while predicting nontrivial optical effects. In this work, we investigate optical effects in ModMax electrodynamics in the presence of an external electromagnetic field. Considering uniform and constant magnetic and electric backgrounds, the solutions for the refractive indices are revisited. Using these results, we obtain the propagating modes and the phase shift (birefringence) for plane wave solutions in the presence of a pure magnetic background field. Afterwards, we investigate the Goos-H\"anchen effect considering the interface between a simple dielectric and a medium whose electromagnetic response tensors are ruled by the ModMax electrodynamics. Further, based on the general reflection problem, we discuss the complex Kerr rotation with both the electric (E) and magnetic (B) background fields, considering two main cases: i) $B > E$ and ii) $E > B$. Our findings indicate that the $\gamma$ parameter and the ratios (B/E) and (E/B) play a central role in describing the Kerr signals (rotation and ellipticity) of systems with optical effects induced by nonlinear electromagnetic interactions.

physics.optics↗

arXiv2026

Electric birefringence in Euler-Heisenberg pseudo-electrodynamics

The fermion sector of the pseudo-quantum electrodynamics is integrated functionally to generate a non-linear electrodynamics, that it is called Euler-Heisenberg pseudo-electrodynamics. A non-local Chern-Simons topological term is added to the original lagrangian of the pseudo-quantum electrodynamics in which a most complete electrodynamics gauge invariant in 1+2 dimensions is proposed. As consequence of the fermionic sector, we obtain a non-linear contribution in the electromagnetic fields that breaks the Lorentz symmetry due to Fermi velocity. From the Euler-Heisenberg pseudo-electrodynamics, we study the properties of the plane wave propagating in a planar medium under an uniform and constant electromagnetic background field. The properties of the planar material are discussed through the electric permittivity tensor and magnetic permeability, that are functions of the frequency, wavelength and of the background fields. The dispersion relations and the refractive index are calculated in the presence of a uniform magnetic field, and also in the case only of an electric background field. The birefringence phenomenon emerges only when the electric background field is considered.

hep-th↗

arXiv2026

Thermostatistical analysis and negative heat capacities of Yukawa and Lee-Wick potentials in noncommutative phase spaces

In recent years, physical models based on noncommutative algebras have attracted considerable interest, as they provide a natural framework to incorporate a fundamental scale, often associated with semiclassical aspects of quantum gravity. Noncommutative geometry modifies the underlying phase-space structure, potentially leading to new insights into unresolved problems in theoretical physics. In this work, we adopt a semiclassical approach to perform a thermostatistical analysis of well-established interaction models, namely the Yukawa and Lee--Wick potentials, within a noncommutative phase space. We investigate how phase-space deformations affect the density of states, partition function, mean energy, and heat capacity, considering both microcanonical and canonical ensembles within the Boltzmann--Gibbs framework. Our results show that the introduction of the noncommutative parameter $\Theta$ induces nontrivial modifications in thermodynamic quantities, including qualitative changes in the heat capacity. In particular, regions with negative heat capacity may emerge, which we interpret as signatures of the limitations of the semiclassical and perturbative treatment rather than definitive physical effects. The analysis is carried out under the assumption of weak noncommutativity and $|\beta V(r)| \ll 1$, which constrains the regime of validity of the results. Within this domain, our findings highlight the role of phase-space geometry in shaping thermodynamic behavior.

hep-th↗

arXiv2025

Effective potential of scalar Lee-Wick pseudo-electrodynamics

The study of effective potential for the scalar Lee-Wick pseudo-electrodynamics in one-loop is presented in this letter. The planar and non-local Lee-Wick pseudo-electrodynamics is so coupled to a complex scalar field sector in 1+2 dimensions, where we achieve the Lee-Wick pseudo-scalar electrodynamics. The effective action formalism is applied such that the quantum corrections are examined in one loop to the scalar effective potential as function of the classical field, of the Lee-Wick mass, and also of the coupling constants of this model. The instability of the effective potential is investigated due to Lee-Wick mass.

hep-th↗

arXiv2025

Remarks on classical pseudo-electrodynamics

Classical studies as the conservation laws and the radiation fields are investigated in the pseudo-electrodynamics. We explore the action symmetry under infinitesimal transformations to obtain the energy-momentum, the Belinfante-Rosenfeld, and the general angular momentum tensors for this nonlocal planar electrodynamics. Through the results such as the retarded potentials and fields generated by a point particle in an arbitrary motion, we study the radiation of an electric dipole and it radiated power in 1+2 dimensions. In addition, we propose a way to introduce magnetic monopoles in pseudo-electrodynamics, in which the solutions and conservation laws are also presented.

physics.class-ph↗

arXiv2025

The Lee-Wick-Chern-Simons pseudo-quantum electrodynamics

The Lee-Wick pseudo-quantum electrodynamics in the presence of a Chern-Simons term is studied in this paper. The paper starts with a non-local lagrangian density that sets the pseudo-Lee-Wick electrodynamics defined on a $1+2$ space-time added to a non-local Chern-Simons topological term. Thus, we obtain the Lee-Wick-Chern-Simons pseudo-electrodynamics as a most complete gauge invariant model that provides a light mass associated with the Chern-Simons parameter, and also includes a Lee-Wick heavy mass. We investigate classical aspects as the potential energy for the interaction of static charges through the gauge propagator. The causality of theory is discussed through the retarded Green function in the coordinate space. The gauge field of the Lee-Wick-Chern-Simons pseudo-electrodynamics is minimally coupled to the fermions sector that includes new degree of freedoms, as a Lee-Wick heavy fermion partner of the electron. The perturbative approach for the theory is presented via effective action in which we obtain the Ward identities. We study the quantum corrections at one loop, as the electron self-energy, the vacuum polarization, and the $3$-vertex. We show that the Lee-Wick mass has a fundamental role in these results, where it works like a natural regulator of the ultraviolet divergences. The $g-2$ factor for the electron is obtained as function of the LW mass, and of the CS parameter. Through the optical theorem, the Lee-Wick-Chern-Simons pseudo-electrodynamics is unitary at the tree level.

hep-th↗

arXiv2025

Poisson electrodynamics on $κ$-Minkowski space-time

Poisson electrodynamics is the semi-classical limit of $U(1)$ non-commutative gauge theory. It has been studied so far as a theoretical model, where an external field would be the source of the non-commutative effects in space-time. Being the Standard Model of fundamental interactions a local theory, the prediction of observables within it would be drastically altered by such effects. The natural question that arises is: how do particles interact with this field ? In this work, we will answer this question using point-like charged particles interacting with the Poisson gauge field, investigating how their trajectories are affected using the $κ$-Minkowski structure. The interaction arises from the construction of a gauge-invariant action. Using the field solutions, we find the second-order equation for the deformed Lorentz force, indicating possible effects of an emergent gravity due to non-commutativity.

hep-th↗

arXiv2025

Classical features, Anderson-Higgs mechanism, and unitarity in Lee-Wick pseudo-electrodynamics

In this paper, the dimensional reduction is applied to the Lee-Wick electrodynamics in which the classical sources are confined on a spatial plane. As result, the Lee-Wick pseudo-electrodynamics is achieved as a non-local electromagnetism defined in $1+2$ dimensions. The abelian Anderson-Higgs mechanism is so introduced in the Lee-Wick pseudo-electrodynamics through a complex scalar sector in $1+2$ dimensions, breaking spontaneously the $U(1)$-gauge symmetry of the non-local theory. As consequence, the pseudo-Lee-Wick field acquires a light mass, beyond the usual heavy Lee-Wick mass, that is a natural mass parameter of the theory. After the spontaneous symmetry breaking takes place, classical features of the theory are discussed, as the Proca-Lee-Wick pseudo-electrodynamics, with the field equations and conservation laws. The introduction of Lee-Wick fermions also is proposed, in which it opens the discussion of a viable Proca-Lee-Wick pseudo-quantum electrodynamics in $1+2$ dimensions. The unitarity at the tree level of the Lee-Wick pseudo-electrodynamics is discussed through the Optical theorem.

hep-th↗

arXiv2024

First-order phase-transition on dynamical Lorentz symmetry breaking system

A model of $N$ 4-component massless fermions in a quartic self-interaction based on ref. \cite{gomes2022} is investigated in the presence of chemical potential and temperature via optimized perturbation theory that accesses finite-N contributions. We use the generating functional approach to calculate the corrections to the effective potential of the model. The model introduces an auxiliary pseudo-vector field with a nontrivial minimum and is influenced by temperature $(T)$ and chemical potential $(μ)$. These thermodynamic quantities are introduced through Matsubara formalism. Thereby, the integrals are modified, and via the principle of minimum sensitivity, we obtain the gap equations of the model. The correspondent finite-N solutions of these equations define the vacuum states of the model associated with the background pseudo-vector field. In particular, one focuses on its temporal component that acts as an effective chiral chemical potential. We discuss the solutions of the four cases in which $(T = 0,μ= 0)$, $(T \neq 0,μ\neq 0)$, $(T \neq 0,μ= 0)$ and $(T = 0,μ\neq 0)$, where the effective potential is so obtained as a function of the background vector field, the chemical potential, and the temperature. The model shows the finite-N corrections generate first-order phase transitions on the self-interacting fermions for the case $N=1$ and the persistence of a second-order phase transition for $N \geq 2$.

hep-th↗

arXiv2024

Dispersion and absorption effects in the linearized Euler-Heisenberg electrodynamics under an external magnetic field

The effects of the Ohmic and magnetic density currents are investigated in the linearized Euler-Heisenberg electrodynamics. The linearization is introduced through an external magnetic field, in which the vector potential of the Euler-Heisenberg electrodynamics is expanded around of a magnetic background field, that we consider uniform and constant in this paper. From the Euler-Heisenberg linearized equations, we obtain the solutions for the refractive index associated with the electromagnetic wave superposition, when the current density is ruled by the Ohm law, and in the second case, when the current density is set by a isotropic magnetic conductivity. These solutions are functions of the magnetic background $({\bf B})$, of the wave propagation direction $({\bf k})$, it also depends on the conductivity, and on the wave frequency. As consequence, the dispersion and the absorption of plane waves change when ${\bf B}$ is parallel to ${\bf k}$ in relation to the case of ${\bf B}$ perpendicular to ${\bf k}$ in the medium. The characteristics of the refraction index related to directions of ${\bf B}$ and of the wave polarization open a discussion for the birefringence in this medium.

physics.class-ph↗

arXiv2024

Probing the interference between non-linear, axionic and space-time-anisotropy effects in the QED vacuum

We pursue the investigation of a generic non-linear extension of axionic electrodynamics in a Carroll-Field-Jackiw (CFJ) scenario that implements Lorentz-symmetry violation (LSV). The model we inspect consists of an arbitrary non-linear electrodynamic action coupled to the axion field in presence of an anisotropy four-vector that realizes the breaking of Lorentz symmetry under the particle point of view. The non-linear electromagnetic field is expanded around a constant and uniform magnetic background up to second order in the propagating photon field. The focus of our attention is the study of the material properties of the vacuum in the particular case of a space-like CFJ $4$-vector. The dispersion relations associated to the plane wave solutions are explicitly worked out in two situations: the magnetic background perpendicular and parallel to the wave direction. We extend these results to consider the analysis of the birefringence phenomenon in presence of non-linearity, the axion and the LSV manifested through the spatial anisotropy. Three specific proposals of non-linear electrodynamics are contemplated: Euler-Heisenberg, Born-Infeld and the Modified Maxwell electrodynamics. Throughout the paper, we shall justify why we follow the unusual path of connecting, in a single Lagrangian density, three pieces of physics beyond the Standard Model, namely, non-linearity, axions and LSV. Our true goal is to actually inspect and describe how axionic, non-linear and LSV effects interfere with one another whenever physical entities like group velocity, refraction indices, birefringence and effective masses of physical excitations are computed in presence of an external constant and homogeneous magnetic field.

physics.gen-ph↗

arXiv2023

Effects of wave propagation in canonical Poisson gauge theory under an external magnetic field

The non-commutative electrodynamics based on the canonical Poisson gauge theory is studied in this paper. For a pure spatial non-commutativity, we investigate the plane wave solutions in the presence of a constant and uniform magnetic background field for the classical electrodynamics in canonical Poisson gauge theory. We obtain the properties of the medium ruled by the permittivity and the permeability tensors in terms of the non-commutative parameter, with the electrodynamics equations in the momentum space. Using the plane wave solutions mentioned, the dispersion relations are modified by the magnetic background, and the correspondent group velocity is affected by the spatial non-commutative parameter. We construct the energy-momentum tensor and discuss the conserved components of this tensor in the spatial non-commutative case. The birefringence phenomenon is showed through the modified dispersion relations, that depends directly on the non-commutative corrections and also on the magnetic background field. Using the bound of the polarized vacuum with laser (PVLAS) experiment for the vacuum magnetic birefringence, we estimate a theoretical value for the spatial non-commutative parameter.

hep-th↗

arXiv2023

Constraints on Hidden Sectors Using Rare Kaon Decays

The charged Kaon meson ($K^+$) features several hadronic decay modes, but the most relevant contribution to its decay width stems from the leptonic decay $K^+ \rightarrow μ^+ ν_μ$. Given the precision acquired on the rare decay mode $K^+ \rightarrow μ^+ ν_μ+ X$, one can use the data to set constraints on sub-GeV hidden sectors featuring light species that could contribute to it. Light gauge bosons that couple to muons could give rise to sizeable contributions. In this work, we will use data from the $K^+ \rightarrow μ^+ν_μ l^+l^-$, and $K^+ \rightarrow μ^+ ν_μ ν\barν$ decays to place limits on light vector bosons present in Two Higgs Doublet Models (2HDM) augmented by an Abelian gauge symmetry, 2HDM-$U(1)_X$. We put our findings into perpective with collider bounds, atomic parity violation, neutrino-electron scattering, and polarized electron scattering probes to show that rare Kaon decays provide competitive bounds in the sub-GeV mass range for different values of $\tanβ$.

hep-ph↗