A5062001382- Ionosphere and magnetosphere dynamics
- Magnetic confinement fusion research
- Cold Atom Physics and Bose-Einstein Condensates
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Astrophysics and Cosmic Phenomena
- Education and Digital Technologies
- Algebraic structures and combinatorial models
- Science and Education Research
- Quantum, superfluid, helium dynamics
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Geomagnetism and Paleomagnetism Studies
- Advanced Chemical Physics Studies
- Geophysics and Sensor Technology
- Nuclear physics research studies
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Education Pedagogy and Practices
- High-pressure geophysics and materials
- Quantum Information and Cryptography
- Plasma Diagnostics and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Earthquake Detection and Analysis
- Physics of Superconductivity and Magnetism
Universidade Federal de Santa Catarina
2002-2025
University of Lisbon
2016-2024
Instituto Superior Técnico
2023
Universidade Federal Rural do Rio de Janeiro
2017
Universidade do Estado de Santa Catarina
2009
University of Washington
1996
University of Coimbra
1995
Universidade Estadual Paulista (Unesp)
1993
Polydoro Ernani de São Thiago University Hospital
1985-1989
Universidade de São Paulo
1981-1986
Axions can be copiously produced in localized regions of neutron star magnetospheres where the ambient plasma is unable to efficiently screen induced electric field. As these axions stream away from they resonantly transition into photons, generating a large broadband contribution star's intrinsic radio flux. In this Letter, we develop comprehensive end-to-end framework model process initial production final detection and derive constraints on axion-photon coupling, g_{aγγ}, using...
Abstract Relativistic electron-positron plasmas are ubiquitous in extreme astrophysical environments such as black-hole and neutron-star magnetospheres, where accretion-powered jets pulsar winds expected to be enriched with pairs. Their role the dynamics of is many cases believed fundamental, but their behavior differs significantly from typical electron-ion due matter-antimatter symmetry charged components. So far, our experimental inability produce large yields positrons quasi-neutral...
Pulsar magnetospheres are thought to be filled with electron-positron plasma generated in pair cascades. The driving mechanism of these cascades is the emission gamma-ray photons and their conversion into pairs via Quantum Electrodynamics (QED) processes. In this work, we present 2D particle-in-cell simulations pulsar polar caps realistic magnetic field geometry that include relevant QED processes from first principles. Our results show that, due variation curvature across cap, production...
Aims. Global particle-in-cell (PIC) simulations of pulsar magnetospheres are performed with volume-, surface-, and pair-production-based plasma injection schemes to systematically investigate the transition between electrosphere force-free magnetospheric regimes. Methods. We present a new extension PIC code OSIRIS that can be used model two-dimensional axisymmetric spherical grid. The subalgorithms thorough benchmarks presented in detail, including first-order current deposition scheme...
Este artigo apresenta uma análise histórica-epistemológica do estilo orgânico de matematização newtoniana, durante o processo formalização da sua mecânica racional. De acordo com a literatura, problemática educacional, referente abordagem matemática no ensino física diz respeito questão epistemológica e não, estritamente, metodológica. O caminho para nova concepção seria através histórico-epistemológica, papel que desempenha física. Mais ferramenta cálculo, um estrutura, modo revelar...
We apply the nonperturbative optimized linear $\ensuremath{\delta}$ expansion method to $O(N)$ scalar field model in three dimensions determine transition temperature of a dilute homogeneous Bose gas. Our results show that shift $\ensuremath{\Delta}{T}_{c}{/T}_{c}$ interacting model, compared with ideal-gas temperature, really behaves as $\ensuremath{\gamma}{\mathrm{an}}^{1/3}$ where is s-wave scattering length and n number density. For $N=2$ our calculations yield value $\ensuremath{\gamma}=3.059.$
ABSTRACT Investigation of the lunar crustal magnetic anomalies offers a comprehensive long-term data set observations small-scale fields and their interaction with solar wind. In this paper review mini-magnetospheres is compared quantifiably theoretical kinetic-scale plasma physics 3D particle-in-cell simulations. The aim to provide complete picture all aspects phenomena show how from different international missions interrelate. analysis shows that simulations are consistent formation...
We present ab initio global general-relativistic Particle-in-cell (GR-PIC) simulations of compact millisecond neutron star magnetospheres in the axisymmetric aligned rotator configuration. investigate role GR and plasma supply on polar cap particle acceleration efficiency - precursor coherent radio emission employing a new module for PIC code OSIRIS, designed to model dynamics around objects with fully self-consistent effects. provide detailed description main sub-algorithms novel algorithm,...
We use the nonperturbative linear \delta expansion method to evaluate analytically coefficients c_1 and c_2^{\prime \prime} which appear in for transition temperature a dilute, homogeneous, three dimensional Bose gas given by T_c= T_0 \{1 + n^{1/3} [ c_2^{\prime} \ln(a n^{1/3}) +c_2^{\prime ] a^2 n^{2/3} {\cal O} (a^3 n)\}, where is result an ideal gas, s-wave scattering length n number density. In previous work same has been used order-\delta^2 with c_1= 3.06. Here, we push calculation next...
Magnetospheres are a ubiquitous feature of magnetized bodies embedded in plasma flow. While large planetary magnetospheres have been studied for decades by spacecraft, ion-scale “mini” can provide unique environment to study kinetic-scale, collisionless physics the laboratory help validate models larger systems. In this work, we present preliminary experiments performed on high-repetition-rate platform developed Large Plasma Device at University California, Los Angeles. The utilize laser...
Time-dependent cascades of electron–positron pairs are thought to be the main source plasma in pulsar magnetospheres and a primary ingredient explain nature radio emission, long-standing open problem high-energy astrophysics. During these cascades—positive feedback loops gamma-ray photon emission via curvature radiation by TeV electrons positrons pair production—the self-consistently develops inductive waves that couple electromagnetic modes capable escaping dense plasma. In this work, we...
Abstract The self-consistent modeling of vacuum polarization due to virtual electron-positron fluctuations is relevance for many near term experiments associated with high intensity radiation sources and represents a milestone in describing scenarios extreme energy density. We present generalized finite-difference time-domain solver that can incorporate the modifications Maxwell’s equations polarization. Our multidimensional reproduced one-dimensional configurations results which an analytic...
A complete irreversible adiabatic transport of Bose-Einstein condensate (BEC) in a double-well trap is investigated within the mean field approximation. The transfer driven by time-dependent (Gaussian) coupling between wells and their relative detuning. protocol successfully works wide range both repulsive attractive BEC interaction. nonlinear effects caused interaction can be turned from detrimental into favorable for transport. results are compared with familiar Landau-Zener scenarios...
We investigate the formation of collisionless magnetized shocks triggered by interaction between plasma flows and miniature-sized (order kinetic-scales) magnetic obstacles resorting to massively parallel, full particle-in-cell simulations, including electron kinetics. The critical obstacle size generate a compressed region ahead these objects is determined independently varying magnitude dipolar moment magnetization. find that effective depends on relative orientation internal fields, we...
Recent advances in numerical algorithms and computational power have enabled first-principles simulations of pulsar magnetospheres using Particle-in-Cell (PIC) techniques. These ab-initio seem to indicate that pair creation through photon-photon collision at the light cylinder is required sustain engine. However, for many rotation-powered pulsars operates effectively only near stellar surface where magnetic field high. How these "weak pulsars" fill their without efficient conversion outer...
The orbital $M1$ collective mode predicted for deformed clusters in a schematic model is studied self-consistent random-phase-approximation approach which fully exploits the shell structure of clusters. microscopic mechanism excitation clarified and close correlation with $E2$ established. study shows that strength fragmented over large energy interval. In spite that, fraction remaining at low energy, well below overwhelming dipole plasmon resonance, comparable to model. importance this...
Abstract Mini-magnetospheres are small ion-scale structures that well suited to studying kinetic-scale physics of collisionless space plasmas. Such magnetospheres can be found on local regions the Moon, associated with lunar crustal magnetic field. In this paper, we report laboratory experimental study reconnection in laser-driven, lunar-like Large Plasma Device at University California, Los Angeles. experiment, a high-repetition rate (1 Hz), nanosecond laser is used drive fast-moving,...
In this paper we propose a methodology for the efficient implementation of machine learning (ML)-based methods in particle-in-cell (PIC) codes, with focus on Monte Carlo or statistical extensions to PIC algorithm. The presented approach allows neural networks be developed Python environment, where advanced ML tools are readily available proficiently train and test them. Those models then efficiently deployed within highly scalable fully parallelized simulations during runtime. We demonstrate...
Fast-exploding plasmas traveling though magnetized, collisionless can occur in a variety of physical systems, such as supernova remnants, coronal mass ejections, and laser-driven laboratory experiments. To study these it is important to understand the coupling process between plasmas. In this work, we develop semi-analytical model parameters that characterize strong an unmagnetized driver plasma uniformly perpendicularly magnetized background plasma. particular, derive analytical expressions...
Neutron stars are usually modelled as spherical, rotating perfect conductors with a predominant intrinsic dipolar magnetic field anchored to their stellar crust. Due compactness, General Relativity corrections must be accounted for in Maxwell's equations, leading modified interior and exterior electromagnetic solutions. We present analytical solutions slowly-rotating magnetised neutron taking into account the frame-dragging correction. For typical compactness values, i.e. $R_s \sim 0.5...
We study the thermodynamics of a two-species homogeneous and dilute Bose gas that are self-interacting quadratically coupled to each other. make use field-theoretical functional integral techniques evaluate one-loop finite-temperature effective potential for this system considering resummation leading-order temperature-dependent as well infrared contributions. The symmetry breaking pattern associated with model is then studied by different values self-species interspecies couplings. pay...
Ion-scale magnetospheres have been observed around comets, weakly-magnetized asteroids, and localized regions on the Moon, provide a unique environment to study kinetic-scale plasma physics, in particular collisionless regime. In this work, we present results of particle-in-cell simulations that replicate recent experiments Large Plasma Device at University California, Los Angeles. Using high-repetition rate lasers, ion-scale were created drive flow into dipolar magnetic field embedded...
Recently, in the Science Education community, it has been a growing collective concern about influence of affective aspects on intellectual activity individuals, particularly, learning and making decision. In this study, we investigate dimension decision to pursue Physics teacher carrier by undergraduates Santa Catarina State University São Paulo University. The research was guided following questions: (1) What career as teacher? (2) are key emotional experiences that motivate choice (3)...