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We demonstrate the sensitivity of magnetic energy and helicity computations regarding the quality of the underlying coronal magnetic field model. We apply the method of Wiegelmann & Inhester (2010) to a series of SDO/HMI vector…

Solar and Stellar Astrophysics · Physics 2019-07-24 Julia K. Thalmann , Luis Linan , Etienne Pariat , Gherardo Valori

A scheme is developed which shows how one would, given a light-front Hamiltonian for QCD, extract the $Q\overline{Q}$ potential, i.e. the quantity which corresponds to the potential between two infinitely heavy quarks in a rest frame, from…

High Energy Physics - Phenomenology · Physics 2016-09-01 Matthias Burkardt

We propose a new mixed finite element method for the three-dimensional steady magnetohydrodynamic (MHD) kinematics equations for which the velocity of the fluid is given. Although prescribing the velocity field leads to a simpler model than…

Numerical Analysis · Mathematics 2017-12-29 Lingxiao Li

We present a first application of the recently proposed LITMUS test for magnetic helicity, as well as a thorough study of its applicability under different circumstances. In order to apply this test to the galactic magnetic field, the newly…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 N. Oppermann , H. Junklewitz , G. Robbers , T. A. Enßlin

Magnetic fields of laboratory, planetary, stellar, and galactic plasmas commonly exhibit significant order on large temporal or spatial scales compared to the otherwise random motions within the hosting system. Such ordered fields can be…

Solar and Stellar Astrophysics · Physics 2015-06-18 Eric G. Blackman

Aims. The main aim of this work is to study the evolution of the recently introduced relative helicity of the magnetic polarity inversion line (PIL) in a magnetohydrodynamics simulation. Methods. The simulation used is a typical flux…

Solar and Stellar Astrophysics · Physics 2024-09-05 K. Moraitis , V. Archontis , G. Chouliaras

We propose a new finite element method for linearized Magnetohydrodynamics. The main novelty is that the proposed scheme is able to handle also non-convex domains and less regular solutions. The method is proved to be pressure robust and…

Numerical Analysis · Mathematics 2025-06-10 L. Beirao da Veiga , C. Lovadina , M. Trezzi

The emergence of dipolar magnetic features on the solar surface is an idealization. Most of the magnetic flux emergence occurs in complex multipolar regions. Here, we show that the surface pattern of magnetic structures alone can reveal the…

Solar and Stellar Astrophysics · Physics 2018-12-11 Philippe-A. Bourdin , Axel Brandenburg

Compressible ideal magnetohydrodynamics (MHD) is formulated in terms of the time evolution of potential vorticity and magnetic flux per unit mass using a compact Lie bracket notation. It is demonstrated that this simplifies analytic…

Plasma Physics · Physics 2014-02-03 Wayne Arter

We present a new computational method for smoothly matching general relativistic ideal magnetohydrodynamics (MHD) to its force-free limit. The method is based on a flux-conservative formalism for MHD and its force-free limit, and a vector…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Vasileios Paschalidis , Stuart L. Shapiro

Numerical tests of volume formulae are presented to compute efficiently the volume enclosed between flux surfaces for integrable 3D vector fields with various degrees of symmetry. In the process, a new case is proposed and tested.

Dynamical Systems · Mathematics 2025-11-26 David Martinez-del-Rio , Robert S. MacKay

A new magnetization equation recently derived from irreversible thermodynamics is employed to the calculation of an increase of ferrofluid viscosity in a magnetic field. Results of the calculations are compared with those obtained on the…

Soft Condensed Matter · Physics 2009-11-07 Mark I. Shliomis

The average helicity of a given electromagnetic field measures the difference between the number of left- and right-handed photons contained in the field. In here, the average helicity is derived using the conformally-invariant…

Optics · Physics 2019-11-21 Ivan Fernandez-Corbaton

We obtain cubature formulas of volume potentials over bounded domains combining the basis functions introduced in the theory of approximate approximations with their integration over the tangential-halfspace. Then the computation is reduced…

Numerical Analysis · Mathematics 2012-10-29 F. Lanzara , V. Maz'ya , G. Schmidt

We report in this letter our analysis of a large sample of photospheric vector magnetic field measurements. Our sample consists of 17200 vector magnetograms obtained from January 1997 to August 2004 by Huairou Solar Observing Station of the…

Astrophysics · Physics 2009-11-11 Mei Zhang

We extend the foil winding homogenization method to magnetic field conforming formulations. We first propose a full magnetic field foil winding formulation by analogy with magnetic flux density conforming formulations. We then introduce the…

Computational Engineering, Finance, and Science · Computer Science 2026-05-19 Louis Denis , Elias Paakkunainen , Paavo Rasilo , Sebastian Schöps , Benoît Vanderheyden , Christophe Geuzaine

General hyperbolic systems of balance laws with inhomogeneity in space and time in all constitutive functions are studied in the context of relative entropy. A framework is developed in this setting that contributes to a measure-valued weak…

Analysis of PDEs · Mathematics 2022-06-02 Cleopatra Christoforou

We propose an improved effective-medium theory to obtain the concentration dependence of the viscosity of particle suspensions at arbitrary volume fractions. Our methodology can be applied, in principle, to any particle shape as long as the…

Soft Condensed Matter · Physics 2010-06-01 I. Santamaria-Holek , Carlos I. Mendoza

Magnetic helicity is approximately conserved in resistive MHD models. It quantifies the entanglement of the magnetic field within the plasma. The transport and removal of helicity is crucial in both the dynamo in the solar interior and…

Solar and Stellar Astrophysics · Physics 2020-03-25 Christopher Prior , Gareth Hawkes , Mitch Berger

It is shown that the helicity of three dimensional viscous incompressible flow can be identified with the overall linking of the fluid's initial vorticity to the expectation of a stochastic mean field limit. The relevant mean field limit is…

Fluid Dynamics · Physics 2022-06-20 Simon Hochgerner