English
Related papers

Related papers: Magnetic helicity in multiply connected domains

200 papers

Expanding on an earlier work that relied on linear force-free magnetic fields, we self-consistently derive the instantaneous free magnetic energy and relative magnetic helicity budgets of an unknown three-dimensional nonlinear force-free…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. K. Georgoulis , K. Tziotziou , N. -E. Raouafi

A formal symplectic structure on RxM is constructed for the unsteady flow of an incompressible viscous fluid on a three dimensional domain M. The evolution equation for the helicity density is expressed via the divergence of the Liouville…

Mathematical Physics · Physics 2007-05-23 Hasan Gumral

We study the magnetic helicity evolution in neutron stars (NSs). First, we analyze how the surface terms affect the conservation law for the sum of the chiral imbalance of the charged particle densities and the density of the magnetic…

High Energy Astrophysical Phenomena · Physics 2024-01-29 Maxim Dvornikov

The recent years have witnessed an emergence of the field of all-spin-based devices without any flow of charge. An ultimate goal of this scientific direction is the realization of full spectrum of spin-based networks like in modern…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 E. Vedmedenko , D. Altwein

The paper describes the unique geometric properties of ideal magnetohydrodynamics (MHD), and demonstrates how such features are inherited by extended MHD, viz. models that incorporate two-fluid effects (the Hall term and electron inertia).…

Plasma Physics · Physics 2016-06-03 Manasvi Lingam , George Miloshevich , Philip J. Morrison

It is shown that in magnetohydrodynamics, the shapes of the magnetic energy and magnetic helicity spectra can influence whether the magnetic helicity resistive dissipation time scale is longer, equal to, or shorter than that of magnetic…

Astrophysics · Physics 2015-06-24 Eric G. Blackman

The most important factors determining solar coronal activity are believed to be the availability of magnetic free energy and the constraint of magnetic helicity conservation. Direct measurements of the helicity and magnetic free energy in…

Solar and Stellar Astrophysics · Physics 2019-09-25 Peter W. Schuck , Spiro K. Antiochos

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

Spin-orbit torque provides a powerful means of manipulating domain walls along magnetic wires. However, the current density required for domain wall motion is still too high to realize low power devices. Here we experimentally demonstrate…

Mesoscale and Nanoscale Physics · Physics 2019-03-06 Boyu Zhang , Yong Xu , Weisheng Zhao , Daoqian Zhu , Xiaoyang Lin , Michel Hehn , Gregory Malinowski , Dafiné Ravelosona , Stéphane Mangin

Helicity is a property of light which is familiar from particle physics but less well-known in optics. In this paper we recall the explicit form taken by the helicity of light within classical electromagnetic theory and reflect upon some of…

Optics · Physics 2015-06-16 Robert P. Cameron , Stephen M. Barnett , Alison M. Yao

A three-dimensional numerical computation of magnetohydrodynamic dynamo behavior is described. The dynamo is mechanically forced with a driving term of the Taylor-Green type. The magnetic field development is followed from negligibly small…

Astrophysics · Physics 2007-05-23 P. D. Mininni , Y. Ponty , D. C. Montgomery , J. -F. Pinton , H. Politano , A. Pouquet

For certain families of fluid flow, a new conserved quantity -- stream-helicity -- has been established.Using examples of linked and knotted streamtubes, it has been shown that stream-helicity does, in certain cases, entertain itself with a…

Fluid Dynamics · Physics 2009-11-13 Sagar Chakraborty

In the past few years suggestions have emerged that the solar magnetic field might have a bi-helical component with oppositely polarized magnetic fields at large and small scales, and that the shedding of such fields may be crucial for the…

Astrophysics · Physics 2009-11-07 T. A. Yousef , A. Brandenburg

We show that oppositely directed fluxes of energy and magnetic helicity coexist in the inertial range in fully developed magnetohydrodynamic (MHD) turbulence with small-scale sources of magnetic helicity. Using a helical shell model of MHD…

Plasma Physics · Physics 2015-06-23 Rodion Stepanov , Peter Frick , Irina Mizeva

Dynamical studies of MHD turbulence on the one hand, and arguments based upon magnetic helicity on the other, have yielded seemingly contradictory estimates for the $\alpha$ parameter in turbulent dynamo theory. Here we show, with direct…

Astrophysics · Physics 2007-05-23 Hongsong Chou , George B. Field

We continue our construction of a hydrodynamical description of a holographic model with broken translation invariance. Using the fluid/gravity correspondence we derive the constitutive relations of the boundary theory in the presence of a…

High Energy Physics - Theory · Physics 2015-08-14 Mike Blake

Over the years, web content has evolved from simple text and static images hosted on a single server to a complex, interactive and multimedia-rich content hosted on different servers. As a result, a modern website during its loading time…

Social and Information Networks · Computer Science 2022-12-22 Costas Iordanou , Fragkiskos Papadopoulos

In this paper we investigate the dynamics of magnetic helicity in magnetohydrodynamic (MHD) turbulent flows focusing at scales larger than the forcing scale. Our results show a nonlocal inverse cascade of magnetic helicity, which occurs…

Fluid Dynamics · Physics 2017-05-23 Moritz Linkmann , Vassilios Dallas

In the presence of magnetic helicity, inverse transfer from small to large scales is well known in magnetohydrodynamic (MHD) turbulence and has applications in astrophysics, cosmology, and fusion plasmas. Using high resolution direct…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-23 Axel Brandenburg , Tina Kahniashvili , Alexander G. Tevzadze

We use holography to derive effective theories of fluctuations in spontaneously broken phases of systems with finite temperature, chemical potential, magnetic field and momentum relaxation in which the order parameters break translations.…

High Energy Physics - Theory · Physics 2021-06-16 Aristomenis Donos , Christiana Pantelidou , Vaios Ziogas