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Author Araujo Filho, A.A.; Nascimento, J.R.; Petrov, A.Y.; Porfírio, P.J.
Title Vacuum solution within a metric-affine bumblebee gravity Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 108 Issue 8 Pages 085010 - 13pp
Keywords
Abstract We consider a metric-affine extension to the gravitational sector of the Standard Model extension for the Lorentz-violating coefficients u and s(mu nu). The general results, which are applied to a specific model called metric-affine bumblebee gravity, are obtained. A Schwarzschild-like solution, incorporating effects of the Lorentz symmetry breaking through the coefficient X = xi b(2), is found. Furthermore, a complete study of the geodesic trajectories of particles is accomplished in this background, emphasizing the departure from general relativity. We also compute the advance of Mercury's perihelion and the deflection of light within the context of the weak-field approximation, and we verify that there exist two new contributions ascribed to the Lorentz symmetry breaking. As a phenomenological application, we compare our theoretical results with observational data in order to estimate the coefficient X.
Address [Araujo Filho, A. A.; Nascimento, J. R.; Petrov, A. Yu.; Porfirio, P. J.] Univ Fed Paraiba, Dept Fis, Caixa Postal 5008, BR-58051970 Joao Pessoa, Paraiba, Brazil, Email: dilto@fisica.ufc.br;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference (up)
Notes WOS:001151350300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5932
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Author Amarilo, K.M.; Ferreira Filho, M.B.; Araujo Filho, A.A.; Reis, J.A.A.S.
Title Gravitational waves effects in a Lorentz-violating scenario Type Journal Article
Year 2024 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 855 Issue Pages 138785 - 7pp
Keywords Gravitational waves; Lorentz symmetry breaking; Polarization states; Quadrupole term
Abstract This paper focuses on how the production and polarization of gravitational waves are affected by spontaneous Lorentz symmetry breaking, which is driven by a self-interacting vector field. Specifically, we examine the impact of a smooth quadratic potential and a non-minimal coupling, discussing the constraints and causality features of the linearized Einstein equation. To analyze the polarization states of a plane wave, we consider a fixed vacuum expectation value (VEV) of the vector field. Remarkably, we verify that a space-like background vector field modifies the polarization plane and introduces a longitudinal degree of freedom. In order to investigate the Lorentz violation effect on the quadrupole formula, we use the modified Green function. Finally, we show that the space-like component of the background field leads to a third-order time derivative of the quadrupole moment, and the bounds for the Lorentz-breaking coefficients are estimated as well.
Address [Amarilo, K. M.; Ferreira Filho, M. B.] Univ Estado Rio de Janeiro, Dep Fis Nucl & Altas Energias, Inst Fis, Rua Sao Francisco Xavier 524, BR-20559900 Rio De Janeiro, RJ, Brazil, Email: kevin.amarilo@cern.ch;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference (up)
Notes WOS:001257664300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6168
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Author Heidari, N.; Hassanabadi, H.; Araujo Filho, A.A.; Kriz, J.
Title Exploring non-commutativity as a perturbation in the Schwarzschild black hole: quasinormal modes, scattering, and shadows Type Journal Article
Year 2024 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 84 Issue 6 Pages 566 - 11pp
Keywords
Abstract In this work, by a novel approach to studying the scattering of a Schwarzschild black hole, the non-commutativity is introduced as perturbation. We begin by reformulating the Klein-Gordon equation for the scalar field in a new form that takes into account the deformed non-commutative spacetime. Using this formulation, an effective potential for the scattering process is derived. To calculate the quasinormal modes, we employ the WKB method and also utilize fitting techniques to investigate the impact of non-commutativity on the scalar quasinormal modes. We thoroughly analyze the results obtained from these different methods. Moreover, the greybody factor and absorption cross section are investigated. Additionally, we explore the behavior of null geodesics in the presence of non-commutativity. Specifically, we examine the photonic, and shadow radius as well as the light trajectories for different non-commutative parameters. Therefore, by addressing these various aspects, we aim to provide a comprehensive understanding of the influence of non-commutativity on the scattering of a Schwarzschild-like black hole and its implications for the behavior of scalar fields and light trajectories.
Address [Heidari, N.; Hassanabadi, H.] Shahrood Univ Technol, Fac Phys, Shahrood, Iran, Email: heidari.n@gmail.com
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference (up)
Notes WOS:001239390500007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6191
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Author Araujo Filho, A.A.; Jusufi, K.; Cuadros-Melgar, B.; Leon, G.
Title Dark matter signatures of black holes with Yukawa potential Type Journal Article
Year 2024 Publication Physics of the Dark Universe Abbreviated Journal Phys. Dark Universe
Volume 44 Issue Pages 101500 - 20pp
Keywords Quantum-corrected Yukawa-like gravitational potential; Dark matter; Quasinormal frequencies; Black Holes shadows
Abstract This study uses a nonsingular Yukawa-modified potential to obtain a static and spherically symmetric black hole solution with a cosmological constant. Such Yukawa-like corrections are encoded in two parameters, alpha and lambda, that modify Newton's law of gravity in large distances, and a deformation parameter l(0), which plays an essential role in short distances. The most significant effect is encoded in alpha, which modifies the total black hole mass with an extra mass proportional to alpha M, mimicking the dark matter effects at large distances from the black hole. On the other hand, the effect due to lambda is small for astrophysical values. We scrutinize the quasinormal frequencies and shadows associated with a spherically symmetric black hole and the thermodynamical behavior influenced by the Yukawa potential. In particular, the thermodynamics of this black hole displays a rich behavior, including possible phase transitions. We use the WKB method to probe the quasinormal modes of massless scalar, electromagnetic, and gravitational field perturbations. In order to check the influence of the parameters on the shadow radius, we consider astrophysical data to determine their values, incorporating information on an optically thin radiating and infalling gas surrounding a black hole to model the black hole shadow image. In particular, we consider Sgr A* black hole as an example and we find that its shadow radius changes by order of 10(-9), meaning that the shadow radius of a black hole with Yukawa potential practically gives rise to the same result encountered in the Schwarzschild black hole. Also, in the eikonal regime, using astrophysical data for Yukawa parameters, we show that the value of the real part of the QNMs frequencies changes by 10(-18). Such Yukawa-like corrections are, therefore, difficult to measure by observations of gravitational waves using the current technology.
Address [Filhoa, A. A. Araujo] Univ Valencia, Ctr Mixto Univ Valencia, Dept Fis Teor, CSIC, Burjassot 46100, Valencia, Spain, Email: dilto@fisica.ufc.br;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference (up)
Notes WOS:001287415400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6226
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Author Araujo Filho, A.A.; Hassanabadi, H.; Reis, J.A.A.S.; Lisboa-Santos, L.
Title Fermions with electric dipole moment in curved space-time Type Journal Article
Year 2024 Publication International Journal of Modern Physics A Abbreviated Journal Int. J. Mod. Phys. A
Volume 39 Issue 19n20 Pages 2450078 - 16pp
Keywords Fermions; curved spacetime; electric dipole momentum; thermodynamics
Abstract This paper explores the relativistic behavior of spin-half particles possessing an Electric Dipole Moment (EDM) in a curved space-time background induced by a spiral dislocation. A thorough review of the mathematical formulation of the Dirac spinor in the framework of quantum field theory sets the foundation for our investigation. By deriving the action that governs the interaction between the spinor field, the background space-time, and an external electric field, we establish a framework to study the dynamics of the system. Solving the resulting wave equation reveals a set of coupled equations for the radial components of the Dirac spinor, which give rise to a modified energy spectrum attributed to the EDM. To validate our findings, we apply them to the geometric phase and thermodynamics.
Address [Araujo Filho, A. A.] Univ Valencia, Ctr Mixto Univ Valencia, CSIC, Dept Fis Teor, Valencia 46100, Spain, Email: dilto@fisica.ufc.br;
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-751x ISBN Medium
Area Expedition Conference (up)
Notes WOS:001302405200007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6243
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