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The configuration and evolution of the magnetic field in star-forming cores are investigated in order to directly compare simulations and observations. We prepare four different initial clouds having different magnetic field strengths and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Akimasa Kataoka , Masahiro N. Machida , Kohji Tomisaka

The macroscopic properties of compact stars in modified gravity theories can be significantly different from the general relativistic (GR) predictions. Within the gravitational context of scalar-tensor theories, with a scalar field $\phi$…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , Sergio B. Duarte , José D. V. Arbañil

Conditions of optimal (synchronized) collisions of any number of solitons and breathers are studied within the framework of the Gardner equation with positive cubic nonlinearity, which in the limits of small and large amplitudes tends to…

Pattern Formation and Solitons · Physics 2018-08-30 Alexey Slunyaev

Cylindrical coordinates are often used in computational fluid dynamics, in particular, when one considers gas flow accreting onto a central object. Although the cylindrical coordinates have several advantages in describing rotation, they…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Tomoyuki Hanawa , Yosuke Matsumoto

In this paper we study a general nonlinear Schr\"odinger equation with a time dependent harmonic potential. Despite the lack of traslational invariance we find a symmetry trasformation which, up from any solution, produces infinitely many…

Soft Condensed Matter · Physics 2007-05-23 Juan J. Garcia-Ripoll , Victor M. Perez-Garcia , Vadym Vekslerchik

Following the basic principles of a charge separated pulsar magnetosphere \citep{goldreich1969}, we consider the magnetosphere be stationary in space, instead of corotating, and the electric field be uploaded from the potential distribution…

High Energy Astrophysical Phenomena · Physics 2015-07-01 K. H. Tsui

An oblique pulsar magnetosphere with a plasma conductivity is studied by using a pseudo-spectral method. In the pseudo-spectral method, the time-dependent Maxwell equations are solved, both electric and magnetic fields are expanded in terms…

High Energy Astrophysical Phenomena · Physics 2016-07-27 Gang Cao , Li Zhang , Sineng Sun

A beam of rotating dipolar particles (molecules or clusters) will broaden when passed through an electric or magnetic field gradient region. This broadening, which is a common experimental observable, can be expressed in terms of the…

Atomic and Molecular Clusters · Physics 2012-01-05 Jaap Bulthuis , Vitaly V. Kresin

We have analyzed magnetized equilibrium states and showed a condition for appearance of the prolate and the toroidal magnetic field dominated stars by analytic approaches. Both observations and numerical stability analysis support that the…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Kotaro Fujisawa , Yoshiharu Eriguchi

First observations of electrostatic potential variations within the flux surfaces of a toroidal magnetic confinement device are presented. Measurements are taken in the TJ-II stellarator with two distant Langmuir probe arrays. The edge…

This article introduces a novel method for the implementation of shape optimisation with Lipschitz domains. We propose to use the shape derivative to determine deformation fields which represent steepest descent directions of the shape…

Optimization and Control · Mathematics 2021-12-15 Klaus Deckelnick , Philip J. Herbert , Michael Hinze

We formulate variation principle for force-free magnetosphere of an inclined pulsar: ${\cal E} +{\bf \Omega}\cdot {\bf M}$ ($\cal E$, ${\bf M}$ are electromagnetic energy and angular momentum, ${\bf \Omega}$ is the angular velocity of a…

Astrophysics · Physics 2009-11-11 Andrei Gruzinov

Quasisymmetry (QS) is a hidden symmetry of the magnetic field strength, B, that effectively confines charged particles in a three-dimensional toroidal plasma equilibrium. Here, we show that QS has a deep connection to the underlying…

We present initial results of the first self-consistent numerical model of the outer magnetosphere of a pulsar. By using the relativistic ``particle-in-cell'' method with special boundary conditions to represent plasma dynamics in 3D, we…

Astrophysics · Physics 2007-05-23 Anatoly Spitkovsky , Jonathan Arons

Magnetars are highly magnetized neutron stars. For a slowly rotating magnetar, the strong magnetic field deforms the star, making it axisymmetric with respect to the magnetic axis (the body symmetry axis). In magnetars, the rotation axis is…

High Energy Astrophysical Phenomena · Physics 2021-08-11 Debojoti Kuzur , Ritam Mallick

Magnetospheres of many astrophysical objects can be accurately described by the low-inertia (or "force-free") limit of MHD. We present a new numerical method for solution of equations of force-free relativistic MHD based on the…

Astrophysics · Physics 2011-02-11 Anatoly Spitkovsky

The guiding center and gyrokinetic theory of magnetized particle motion is extended to the regime of large electric field gradients perpendicular to the magnetic field. A gradient in the electric field directly modifies the oscillation…

Plasma Physics · Physics 2021-04-21 Ilon Joseph

Magnetic confinement of stellar winds leads to the formation of magnetospheres, which can be sculpted into Centrifugal Magnetospheres (CMs) by rotational support of the corotating plasma. The conditions required for the CMs of magnetic…

We show that the oscillatory driving of crystal surfaces can induce pattern formation or smoothening. The driving force can be of quite different origin such as a pulsed laser beam, an electric field, or elasticity. Depending on driving…

Statistical Mechanics · Physics 2009-10-31 O. Pierre-Louis , M. I. Haftel

Magnetic fields are constrained by the geometry and location of their sources, limiting the ability to freely tailor their spatial distribution. We introduce a general framework to passively convert the magnetic field generated by arbitrary…