English
Related papers

Related papers: Twisted Magnetic Knots and Links

200 papers

Soft actuators allow to transform external stimuli to mechanical deformations. Because of their deformational response to external magnetic fields, magnetic gels and elastomers represent ideal candidates for such tasks. Mostly, linear…

Soft Condensed Matter · Physics 2020-07-01 Lukas Fischer , Andreas M. Menzel

Magnetic fields are a dynamically important agent for regulating structure formation in the interstellar medium. The study of the relative orientation between the local magnetic field and gas (column-) density gradient has become a powerful…

Astrophysics of Galaxies · Physics 2020-10-14 Bastian Körtgen , Juan D. Soler

The emergence of a large scale magnetic field from randomly forced isotropic strongly helical flows is discussed in terms of the inverse cascade of magnetic helicity and the alpha-effect. In simulations of such flows the maximum field…

Astrophysics · Physics 2007-05-23 Axel Brandenburg

We study the resistive evolution of a localized self-organizing magnetohydrodynamic equilibrium. In this configuration the magnetic forces are balanced by a pressure force caused by a toroidal depression in the pressure. Equilibrium is…

Helical magnetic background fields with adjustable pitch angle are imposed on a conducting fluid in a differentially rotating cylindrical container. The small-scale kinetic and current helicities are calculated for various field geometries,…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Gellert , G. Ruediger , R. Hollerbach

Spin waves are the low-energy excitations of magnetically ordered materials. They are key elements in the stability analysis of the ordered phase and have a wealth of technological applications. Recently, we showed that spin waves of a…

Mesoscale and Nanoscale Physics · Physics 2020-01-08 Chenglong Jia , Decheng Ma , Alexander F. Schäffer , Jamal Berakdar

The inverse cascade of magnetic energy occurs when helicity or rotational instability exists in the magnetohydrodynamic (MHD) system. This well known phenomenon has been considered as a basis for the large scale magnetic field in universe.…

Plasma Physics · Physics 2016-02-16 Kiwan Park

There are observational evidences for the existence of twisted magnetic field in the solar corona. This inspires us to investigate the effect of a twisted magnetic field on the evolution of magnetohydrodynamic (MHD) kink waves in coronal…

Solar and Stellar Astrophysics · Physics 2017-08-29 Zanyar Ebrahimi , Kayoomars Karami , Roberto Soler

Understanding the joint dynamics of electron and nuclear spins is central to core concepts in solid-state magnetic resonance - such as spin-lattice relaxation and dynamic nuclear polarization - but a generalization that capitalizes on…

Quantum Physics · Physics 2021-06-16 Santiago Bussandri , Pablo R. Zangara , Rodolfo H. Acosta , Carlos A. Meriles

Motivated by the empirical finding that the known hemispheric rules for the current helicity at the solar surface are not strict, the excitation of small-scale current helicity by the influence of a large-scale helical magnetic background…

Solar and Stellar Astrophysics · Physics 2016-08-03 Guenther Ruediger , Manfred Kueker

The relaxation of a helical magnetic field ${\bf B}({\bf x}, t)$ in a high-conductivity plasma contained in the annulus between two perfectly conducting coaxial cylinders is considered. The plasma is of low density and its pressure is…

Plasma Physics · Physics 2017-12-06 Henry Keith Moffatt , Krzysztof Andrzej Mizerski

In the absence of an active dynamo, purely poloidal magnetic field configurations are unstable to large-scale dynamical perturbations, and decay via reconnection on an Alfvenic timescale. Nevertheless, a number of classes of dynamo-free…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Ramesh Narayan

(Abridged) We here investigate, by means of fully 3-D Smoothed Particle Magnetohydrodynamic numerical simulations, the effects of magnetic fields on overdense, radiatively cooling, pulsed jets, using different initial magnetic field…

Astrophysics · Physics 2009-11-06 Adriano H. Cerqueira , Elisabete M. de Gouveia Dal Pino

We present the first demonstration of the negative effective magnetic pressure instability in direct numerical simulations of stably stratified, externally forced, isothermal hydromagnetic turbulence in the regime of large plasma beta. By…

Solar and Stellar Astrophysics · Physics 2011-10-05 Axel Brandenburg , Koen Kemel , Nathan Kleeorin , Dhrubaditya Mitra , Igor Rogachevskii

We study chiral fermions electroweakly interacting with a background matter having the nonuniform density and the velocity arbitrarily depending on coordinates. The dynamics of this system is described approximately by finding the Berry…

High Energy Physics - Phenomenology · Physics 2020-05-25 Maxim Dvornikov

Relative magnetic helicity is conserved by magneto-hydrodynamic evolution even in the presence of moderate resistivity. For that reason, it is often invoked as the most relevant constraint to the dynamical evolution of plasmas in complex…

Solar and Stellar Astrophysics · Physics 2020-10-28 Gherardo Valori , Pascal Démoulin , Etienne Pariat , Anthony Yeates , Kostas Moraitis , Luis Linan

Magnetic reconnection is a leading mechanism for magnetic energy conversion and high-energy non-thermal particle production in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron plasmas (e.g.,…

High Energy Astrophysical Phenomena · Physics 2014-11-05 Mickaël Melzani , Rolf Walder , Doris Folini , Christophe Winisdoerffer , Jean M. Favre

We analyze the chiral magnetic effect in a homogeneous neutral plasma from the point of view of energy conservation, and construct an effective potential for the growth of maximally helical perturbations of the electromagnetic field. We…

High Energy Physics - Phenomenology · Physics 2017-07-19 David B. Kaplan , Sanjay Reddy , Srimoyee Sen

The mathematics and physics of each of the three aspects of magnetic field evolution -- topology, energy, and helicity -- is remarkably simple and clear. When the resistivity $\eta$ is small compared to an imposed evolution, $a/v$,…

Plasma Physics · Physics 2023-07-12 Allen H. Boozer

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