scholarly journals Local geometric properties of the lightlike Killing magnetic curves in de Sitter 3-space

2021 ◽  
Vol 6 (11) ◽  
pp. 12543-12559
Author(s):  
Xiaoyan Jiang ◽  
◽  
Jianguo Sun
Keyword(s):  
Magnetic Field ◽  
Local Structure ◽  
Frenet Frame ◽  
De Sitter ◽  
Geometric Properties ◽  
Geometrical Properties ◽  
Magnetic Curve ◽  
Gamma S

<abstract><p>In this article, we mainly discuss the local differential geometrical properties of the lightlike Killing magnetic curve $ \mathit{\boldsymbol{\gamma }}(s) $ in $ \mathbb{S}^{3}_{1} $ with a magnetic field $ \boldsymbol{ V} $. Here, a new Frenet frame $ \{\mathit{\boldsymbol{\gamma }}, \boldsymbol{ T}, \boldsymbol{ N}, \boldsymbol{ B}\} $ is established, and we obtain the local structure of $ \mathit{\boldsymbol{\gamma }}(s) $. Moreover, the singular properties of the binormal lightlike surface of the $ \mathit{\boldsymbol{\gamma }}(s) $ are given. Finally, an example is used to understand the main results of the paper.</p></abstract>

scholarly journals Scalar pair production in a magnetic field in de Sitter universe

2018 ◽  
Vol 78 (5) ◽  
Author(s):  
Mihaela-Andreea Băloi ◽  
Cosmin Crucean ◽  
Diana Popescu
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
De Sitter ◽  
Sitter Universe ◽  
De Sitter Universe

scholarly journals Near-axis expansion of stellarator equilibrium at arbitrary order in the distance to the axis

2020 ◽  
Vol 86 (1) ◽  
Author(s):  
R. Jorge ◽  
W. Sengupta ◽  
M. Landreman
Keyword(s):  
Magnetic Field ◽  
Aspect Ratio ◽  
Magnetic Flux ◽  
Arbitrary Order ◽  
Analytical Framework ◽  
Field Vector ◽  
Magnetic Axis ◽  
Direct Construction ◽  
Geometrical Properties ◽  
Rotational Transform

A direct construction of equilibrium magnetic fields with toroidal topology at arbitrary order in the distance from the magnetic axis is carried out, yielding an analytical framework able to explore the landscape of possible magnetic flux surfaces in the vicinity of the axis. This framework can provide meaningful analytical insight into the character of high-aspect-ratio stellarator shapes, such as the dependence of the rotational transform and the plasma beta limit on geometrical properties of the resulting flux surfaces. The approach developed here is based on an asymptotic expansion on the inverse aspect ratio of the ideal magnetohydrodynamics equation. The analysis is simplified by using an orthogonal coordinate system relative to the Frenet–Serret frame at the magnetic axis. The magnetic field vector, the toroidal magnetic flux, the current density, the field line label and the rotational transform are derived at arbitrary order in the expansion parameter. Moreover, a comparison with a near-axis expansion formalism employing an inverse coordinate method based on Boozer coordinates (the so-called Garren–Boozer construction) is made, where both methods are shown to agree at lowest order. Finally, as a practical example, a numerical solution using a W7-X equilibrium is presented, and a comparison between the lowest-order solution and the W7-X magnetic field is performed.

scholarly journals Charged particle dynamics in the surrounding of Schwarzschild anti-de Sitter black hole with topological defect immersed in an external magnetic field

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Sidra Shafiq ◽  
Saqib Hussain ◽  
Muhammad Ozair ◽  
Adnan Aslam ◽  
Takasar Hussain
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Event Horizon ◽  
Topological Defect ◽  
Magnetic Field Effect ◽  
Topological Defects ◽  
De Sitter ◽  
Relativistic Jets ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

Abstract In this paper, geodesic motion of the charged particles in the vicinity of event horizon of Schwarzschild anti-de-Sitter black hole (BH) with topological defects has been investigated. Weakly magnetized environment is considered in the surrounding of BH which only effects the motion of the particles and doesn’t effect the geometry of the BH. Hence, particles are under the influence of gravity and electromagnetic forces. We have explored the effect of magnetic field on the trajectories of the particles and more importantly on the position of the innermost stable circular orbit. It is observed that the trajectories of the particles in the surrounding of BH are chaotic. Escape conditions of the particles under the influence of gravitomagnetic force are also discussed. Moreover, the escape velocity of particles and its different features have been investigated in the presence and absence of magnetic field. Effect of dark energy on the size of event horizon, mass of the BH and stability of the orbits of the particles have also been explored in detail. These studies can be used to estimate the power of relativistic jets originated from the vicinity of BH.

Jupiter's Interior as Revealed by Juno

2020 ◽  
Vol 48 (1) ◽  
pp. 465-489 ◽  
Author(s):  
David J. Stevenson
Keyword(s):  
Magnetic Field ◽  
Local Structure ◽  
Gravity Data ◽  
Heavy Elements ◽  
Blue Spot ◽  
Helium Gas ◽  
Strong Winds ◽  
Gravitational Compression ◽  
Even Harmonics ◽  
Central Concentration

Jupiter is in the class of planets that we call gas giants, not because they consist of gas but because they were primarily made from hydrogen-helium gas, which upon gravitational compression becomes a metallic fluid. Juno, in orbit about Jupiter since 2016, has changed our view: The gravity data are much improved, and the simplest interpretation of the higher order even harmonics implies that the planet may have a diluted central concentration of heavy elements. Jupiter has strong winds extending to perhaps ∼3,000-km depth that are evident in the odd zonal harmonics of the gravity field. Jupiter's distinctive magnetic field displays some limited local structure, most notably the Great Blue Spot (a region of downward flux near the equator), and some evidence for secular variation, possibly arising from the winds. However, Juno is ongoing; it has not answered all questions and has posed new ones. ▪  Juno's mission reveals Jupiter's interior. ▪  A core exists but is diluted by hydrogen. ▪  The mission revealed wind depth and magnetic field.

Evidence for a Universal Relationship Between Magnetization and Changes in the Local Structure

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3726-3728 ◽  
Author(s):  
L. Downward ◽  
F. Bridges ◽  
D. Cao ◽  
J. Neumeier ◽  
L. Zhou
Keyword(s):  
Magnetic Field ◽  
Distribution Function ◽  
Local Structure ◽  
Pair Distribution Function ◽  
Colossal Magnetoresistance ◽  
X Ray ◽  
Polaron State ◽  
Universal Relationship ◽  
High Fields ◽  
X Ray Absorption

X-ray Absorption Fine Structure (XAFS) measurements of the colossal magnetoresistance (CMR) sample La 0.79 Ca 0.21 MnO 3 at high fields indicate a decrease in the width parameter of the pair distribution function, σ, as the applied magnetic field is increased for T near Tc. The change in σ2 from the disordered polaron state varies approximately exponentially with magnetization irrespective of whether the sample magnetization was achieved through a change in temperature or the application of an external magnetic field. This suggests a more universal relationship between local structure and the sample magnetization than was previously indicated.

scholarly journals Local Structure of the Galactic Magnetic Field

1967 ◽  
Vol 136 (4) ◽  
pp. 347-363 ◽  
Author(s):  
R. G. Bingham ◽  
J. R. Shakeshaft
Keyword(s):  
Magnetic Field ◽  
Local Structure ◽  
Galactic Magnetic Field

scholarly journals 2D relativistic oscillators with a uniform magnetic field in anti-de Sitter space

2021 ◽  
pp. 2150113
Author(s):  
Lakhdar Sek ◽  
Mokhtar Falek ◽  
Mustafa Moumni
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Principal Quantum Number ◽  
Wave Functions ◽  
De Sitter ◽  
Energy Eigenvalues ◽  
Space Deformation ◽  
Klein Gordon ◽  
Sitter Model ◽  
De Sitter Model

We study analytically the two-dimensional deformed bosonic oscillator equation for charged particles (both spin 0 and spin 1 particles) subject to the effect of an uniform magnetic field. We consider the presence of a minimal uncertainty in momentum caused by the anti-de Sitter model and we use the Nikiforov–Uvarov (NU) method to solve the system. The exact energy eigenvalues and the corresponding wave functions are analytically obtained for both Klein–Gordon and scalar Duffin–Kemmer–Petiau (DKP) cases and we find that the deformed spectrum remains discrete even for large values of the principal quantum number. For spin 1 DKP case, we deduce the behavior of the DKP equation and write the nonrelativistic energies and we show that the space deformation adds a new spin-orbit interaction proportional to its parameter. Finally, we study the thermodynamic properties of the system and here we find that the effects of the deformation on the statistical properties are important only in the high-temperature regime.

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