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The amplification of magnetic fields is crucial for understanding the observed magnetization of stars and galaxies. Turbulent dynamo is the primary mechanism responsible for that but the understanding of its action in a collapsing…

Astrophysics of Galaxies · Physics 2026-04-22 Muhammed Irshad P , Pallavi Bhat , Kandaswamy Subramanian , Anvar Shukurov

We report the existence of a new regime for domain wall motion in uniaxial and near-uniaxial ferromagnetic nanowires, characterised by applied magnetic fields sufficiently strong that one of the domains becomes unstable. There appears a new…

Mesoscale and Nanoscale Physics · Physics 2020-02-05 Arseni Goussev , JM Robbins , Valeriy Slastikov , Sergiy Vasylkevych

Context: Convectively-driven flows play a crucial role in the dynamo processes that are responsible for producing magnetic activity in stars and planets. It is still not fully understood why many astrophysical magnetic fields have a…

Solar and Stellar Astrophysics · Physics 2018-05-09 P. J. Bushby , P. J. Käpylä , Y. Masada , A. Brandenburg , B. Favier , C. Guervilly , M. J. Käpylä

A transversally driven isotropic ferromagnet being under the influence of a static external and an uniaxial internal anisotropy field is studied. We consider the dissipative Landau-Lifshitz equation as the fundamental equation of motion and…

patt-sol · Physics 2009-10-28 F. Matthäus , H. Sauermann

To advance our understanding of the magnetohydrodynamic (MHD) processes in liquid metals, in this paper we propose an approach combining the classical methods in the dynamo theory based on numerical simulations of the partial differential…

Fluid Dynamics · Physics 2025-10-16 Francisco Stefano de Almeida , Roman Chertovskih , Sílvio Gama , Rui Gonçalves

Much work on turbulent three-dimensional dynamos has been done using triply periodic domains, in which there are no magnetic helicity fluxes. Here we present simulations where the turbulent intensity is still nearly homogeneous, but now…

Solar and Stellar Astrophysics · Physics 2019-02-20 A. Brandenburg

We obtain high-velocity estimates with error bounds for the scattering operator of the Schr\"odinger equation in three dimensions with electromagnetic potentials in the exterior of bounded obstacles that are handlebodies. A particular case…

Mathematical Physics · Physics 2020-05-22 Miguel Ballesteros , Ricardo Weder

This paper concerns the dynamic stability of the steady 3-D wave structure of a planar normal shock front intersecting perpendicularly to a planar solid wall for unsteady potential flows. The stability problem can be formulated as a free…

Analysis of PDEs · Mathematics 2021-08-23 Beixiang Fang , Feimin Huang , Wei Xiang , Feng Xiao

The kinematic induction equation of MHD is solved numerically in the case of the normal ``111'' ABC flow using a general staggered mesh method. Careful 3-D visualizations of the topology of the magnetic field reveal that previous…

Astrophysics · Physics 2009-10-31 S. B. F. Dorch

For small perturbations of linear Random Dynamical Systems evolving on a Banach space and exhibiting a generalized form of trichotomy, we prove the existence of invariant center manifolds, both in continuous and discrete-time. Furthermore,…

Dynamical Systems · Mathematics 2024-08-05 António J. G. Bento , Helder Vilarinho

The dynamo instability is investigated in the limit of infinite magnetic Prandtl number. In this limit the fluid is assumed to be very viscous so that the inertial terms can be neglected and the flow is slaved to the forcing. The forcing…

Fluid Dynamics · Physics 2015-05-20 Alexandros Alexakis

Results are presented for the phase separation process of a binary mixture subject to an uniform shear flow quenched from a disordered to a homogeneous ordered phase. The kinetics of the process is described in the context of the…

Condensed Matter · Physics 2012-04-05 F. Corberi , G. Gonnella , A. Lamura

We theoretically describe the behavior of a terahertz nano-oscillator based on an anisotropic antiferromagnetic dynamical element driven by spin torque. We consider the situation when the polarization of the spin-current is perpendicular to…

Strongly Correlated Electrons · Physics 2021-07-14 Benjamin Wolba , Olena Gomonay , Volodymyr P. Kravchuk

We study a family of dynamical systems obtained by coupling an Anosov map on the two-dimensional torus -- the chaotic system -- with the identity map on the one-dimensional torus -- the neutral system -- through a dissipative interaction.…

Chaotic Dynamics · Physics 2025-02-26 Federico Bonetto , Guido Gentile

This paper concerns smooth supersonic flows with Lipschitz continuous speed in two-dimensional infinite expanding nozzles, which are governed by a quasilinear hyperbolic equation being singular at the sonic and vacuum state. The flow…

Analysis of PDEs · Mathematics 2014-10-16 Chunpeng Wang , Zhouping Xin

Several one and two dimensional mean field models are analyzed where the effects of current helicity fluxes and boundaries are included within the framework of the dynamical quenching model. In contrast to the case with periodic boundary…

Astrophysics · Physics 2007-05-23 Axel Brandenburg , Kandaswamy Subramanian

We consider a one-dimensional oscillatory medium with a coupling through a diffusive linear field. In the limit of fast diffusion this setup reduces to the classical Kuramoto-Battogtokh model. We demonstrate that for a finite diffusion…

Pattern Formation and Solitons · Physics 2022-05-11 L. A. Smirnov , M. I. Bolotov , D. I. Bolotov , G. V. Osipov , A. Pikovsky

In this work we consider the Lagrangian properties of a random version of the Arnold-Beltrami-Childress (ABC) in a three-dimensional periodic box. We prove that the associated flow map possesses a positive top Lyapunov exponent and its…

Analysis of PDEs · Mathematics 2024-07-26 Michele Coti Zelati , Víctor Navarro-Fernández

Current-induced magnetization dynamics in a trilayer structure composed of two ferromagnetic free layers and a nonmagnetic spacer is examined. Both free layers are treated as a monodomain magnetic body with an uniform agnetization. The…

Materials Science · Physics 2009-11-11 Kiwamu Kudo , Rie Sato , Koichi Mizushima

The self-excitation of magnetic field by a spiral Couette flow between two coaxial cylinders is considered. We solve numerically the fully nonlinear, three-dimensional MHD equations for magnetic Prandtl numbers Pm (ratio of kinematic…

Astrophysics · Physics 2009-11-06 Wolfgang Dobler , Anvar Shukurov , Axel Brandenburg