arXiv subjects

Herondy F. Santana Mota

Publications and source records attributed to Herondy F. Santana Mota.

11 recordsLinked to original sources

arXiv2026

Fermionic Casimir memory from an anisotropic gravitational pulse

We investigate the late-time energy deposited by a weak, spatially homogeneous anisotropic gravitational pulse in a massless Dirac field confined between two static parallel plates. The field satisfies MIT bag boundary conditions, while the prescribed geometry approaches Minkowski spacetime in both asymptotic time regions. Using a tetrad formulation, we show that the linear spin-connection contribution cancels for the traceless anisotropy, leaving a coupling to the shear component of the Dirac stress tensor. The pulse produces real fermion--antifermion pairs, whose deposited energy is evaluated through the corresponding Bogoliubov coefficients. Subtracting the production in unbounded space isolates a finite boundary-dependent contribution governed by the pulse duration relative to the characteristic spectral timescale set by the MIT gap. This contribution is negative in the adiabatic regime, where confinement suppresses excitations relative to the continuous free spectrum, and approaches zero from above in the impulsive limit. The resulting pressure correction is nonmonotonic and exhibits two sign changes, alternately reinforcing and reducing the ordinary attractive Casimir force. Unlike the bosonic vacuum-polarization memory previously obtained for the same class of backgrounds, the present effect is a dissipative fermionic memory carried by gravitationally created pairs. Here, memory denotes the persistent late-time modification of the quantum state after the pulse has vanished.

gr-qc↗

arXiv2025

Vacuum Energy and Topological Mass in Interacting Elko and Scalar Field Theories

In this paper, we consider a four-dimensional system composed of a mass-dimension-one fermionic field, also known as Elko, interacting with a real scalar field. Our main objective is to analyze the Casimir effects associated with this system, assuming that both the Elko and scalar fields satisfy Dirichlet boundary conditions on two large parallel plates separated by a distance $L$. In this scenario, we calculate the vacuum energy density and its first-order correction in the coupling constants of the theory. Additionally, we consider the mass correction for each field separately, namely the topological mass that arises from the boundary conditions imposed on the fields and which also depends on the coupling constants. To develop this analysis, we use the mathematical formalism known as the effective potential, expressed as a path integral in quantum field theory.

hep-th↗

arXiv2025

Vacuum Energy and Topological Mass from a Constant Magnetic Field and Boundary Conditions in Coupled Scalar Field Theories

We investigate the combined effects of a uniform magnetic field and boundary conditions on vacuum energy and topological mass generation in a coupled scalar field theory. The system consists of a real scalar field, subject to Dirichlet boundary conditions, interacting via self- and cross-couplings with a gauge-coupled complex scalar field obeying mixed boundary conditions between two perfectly reflecting parallel plates. The magnetic field induces Landau quantization, leading to novel contributions. Employing zeta-function regularization within the effective potential formalism, we derive the renormalized effective potential up to second order in the coupling constants without imposing a vanishing magnetic field in the renormalization scheme. Our renormalization approach preserves magnetic contributions while properly removing divergences, enabling a consistent treatment of finite-size corrections, magnetic effects, and interaction terms. We compute the vacuum energy per unit area of the plates, analyze the emergence of a topological mass from boundary and magnetic contributions, and evaluate the first-order coupling-constant corrections at two-loop order. Detailed asymptotic analysis are presented for both weak- and strong-field regimes, revealing exponential suppression at high magnetic fields and nontrivial polynomial and logarithmic behavior in the weak-field limit.

hep-th↗

arXiv2024

Vacuum energy density for interacting real and complex scalar fields in a Lorentz symmetry violation scenario

In this paper the vacuum energy density and generation of topological mass are investigated for a system of a real and complex scalar fields interacting with each other. In addition to that, it is also included the quartic self-interaction for each one of the fields. The condition imposed on the real field is the periodic condition, while the complex field obey a quasi-periodic condition. The system is placed in a scenario where the CPT-even aether-type Lorentz symmetry violation takes place. We allow that the Lorentz violation affects the fields with different intensities. The vacuum energy density, its loop correction, and the topological mass are evaluated analytically. It is also discussed the possibility of different vacuum states and their corresponding stability requirements, which depends on the conditions imposed on the fields, the interaction coupling constants and also the Lorentz violation parameters. The formalism used here to perform this investigation is the effective potential one, which is written as a loop expansion via path integral in quantum field theory.

hep-th↗

arXiv2023

Casimir effect, loop corrections and topological mass generation for interacting real and complex scalar fields in Minkowski spacetime with different conditions

In this paper the Casimir energy density, loop corrections, and generation of topological mass are investigated for a system consisting of two interacting real and complex scalar fields. The interaction considered is the quartic interaction in the form of a product of the modulus square of the complex field and the square of the real field. In addition, it is also considered the self-interaction associated with each field. In this theory, the scalar field is constrained to always obey periodic condition while the complex field obeys in one case a quasiperiodic condition and in other case mixed boundary conditions. The Casimir energy density, loop corrections, and topological mass are evaluated analytically for the massive and massless scalar fields considered. An analysis of possible different stable vacuum states and the corresponding stability condition is also provided. In order to better understand our investigation, some graphs are also presented. The formalism we use here to perform such investigation is the effective potential, which is written as loop expansions via path integral in quantum field theory.

hep-th↗

arXiv2023

Quantum Brownian motion induced by an inhomogeneous tridimensional space and a $S^1\times R^3$ topological space-time

In this paper we investigate the Quantum Brownian motion of a point particle induced by quantum vacuum fluctuations of a massless scalar field in (3 + 1)-dimensional Minkowski spacetime with distinct conditions (Dirichlet, Neumann, mixed and quasiperiodic). The modes of the field are confined and compactified to a finite length region, which consequently provides a natural measure scale for the system. Useful expressions for the Wightman function have been obtained, which allow us to calculate analytical expressions for the velocity dispersion in all condition cases considered. We also obtain expressions for the velocity dispersion in the short and late time regimes. Finally, we exhibit some graphs in order to show the behavior of the velocity dispersions, discussing important divergencies that are present in our results.

hep-th↗

arXiv2022

Loop correction to the scalar Casimir energy density and generation of topological mass due to a helix boundary condition in a scenario with Lorentz violation

In this paper the effective potential approach in quantum field theory is used in order to investigate self-interaction loop correction to the Casimir energy density and generation of topological mass for both massless and massive real scalar fields. It is assumed that the scalar field obeys a helix boundary condition. In addition, it is also considered a CPT-even aether-type violation of the Lorentz symmetry. In the absence of the Lorentz violation we obtain analytical expressions for the loop correction to the Casimir energy density and to the mass of the scalar field. The same expressions are also obtained assuming the Lorentz violation in each of the spacetime directions. We also show some graphs that exhibit how the loop correction and the Lorentz violation affect the the Casimir energy density and the mass of the scalar field.

hep-th↗

arXiv2022

Thermal Casimir effect in a classical liquid in a quasi-periodically identified conical spacetime

In this paper, we study the finite-temperature quantum fluctuation of a classical liquid induced by the topology of an effective conical spacetime, as well as by a quasi-periodic boundary condition. The conical spacetime could be either a disclination or a cosmic string. In this context, we consider a phonon field representing quantum excitations of the liquid density, which obeys an effective Klein- Gordon equation with the sound velocity replaced by the light velocity. We obtain closed analytic expressions for the thermal Hadamard function, and consequently, the renormalized mean square density fluctuation of the liquid along with thermodynamics quantities such as internal energy, free energy, total energy, and entropy densities. We also discuss the limiting cases, including low and high-temperature regimes, and the situations in which there are only either the conical spacetime or quasi-periodicity.

hep-th↗

arXiv2021

Ground state energy and topological mass in spacetimes with nontrivial topology

In the present paper, we investigate the ground state energy of a massless scalar field and generation of topological mass by considering a quasi-periodically identified Minkowski spacetime and the `half-Einstein Universe', that is, an Einstein Universe where the massless scalar field propagates under Dirichlet boundary condition. The analysis is performed considering one and two-loop corrections to the effective potential in both cases. Our results are compared with previous results found in literature.

hep-th↗

arXiv2021

Boundary effects on classical liquid density fluctuations

In this paper, we study quantum vacuum fluctuation effects on the mass density of a classical liquid arising from the conical topology of an effective idealized cosmic string spacetime, as well as from the mixed, Dirichlet, and Neumann boundary conditions in Minkowski spacetime. In this context, we consider a phonon field representing quantum excitations of the liquid density, which obeys an effective Klein-Gordon equation with the sound velocity replaced by the light velocity. In the idealized cosmic string spacetime, the phonon field is subject to a quasi-periodic condition. Moreover, in Minkowski spacetime, the Dirichlet and Neumann boundary conditions are applied on one and also two parallel planes. We, thus, in each case, obtain closed analytic expressions for the two-point function and the renormalized mean-squared density fluctuation of the liquid. We point out specific characteristics of the latter by plotting their graphs.

hep-th↗

arXiv2019

Induced Brownian motion by the Friedmann-Robertson-Walker spacetime in the presence of a cosmic string

In this paper we investigate the quantum Brownian motion of a massive scalar point particle induced by the FRW spacetime in the presence of a linear topological defect named cosmic string. In addition, we also consider a flat boundary orthogonal to the defect to analyse its effect on the particle's motion. For both cases we found exact expressions for the renormalized mean square deviation of the particle velocity, the quantity that measures the induced Brownian motion, and obtain asymptotic expressions when the point particle is near and far away from the cosmic string and the boundary. Furthermore, in both cases, there appears divergencies in the mean square deviation of the particle velocity coming from a time interval that correspond to a round trip of the massive point particle between its position and the cosmic string/flat boundary. The number of divergencies depends upon the radial position of the particle and the parameter associated with the cosmic string in the case without boundary, and upon this parameter and the radial and $z$ positions of the particle in the case with boundary.

hep-th↗