English
Related papers

Related papers: Lagrangian approach and dissipative magnetic syste…

200 papers

The Lagrangian formalism for tensor fields over differentiable manifolds with contravariant and covariant affine connections (whose components differ not only by sign) and metrics [$(\bar{L}_n,g)$-spaces] is considered. The functional…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Manoff

We derive the relativistic non-resistive, viscous second-order magnetohydrodynamic equations for the dissipative quantities using the relaxation time approximation. The Boltzmann equation is solved for a system of particles and…

Nuclear Theory · Physics 2021-04-07 Ankit Kumar Panda , Ashutosh Dash , Rajesh Biswas , Victor Roy

Numerical integration of the Landau-Lifshitz-Gilbert equation with thermal fluctuations is used to study the dynamic response of single-domain nanomagnets to rapid changes in the applied magnetic field. The simulation can resolve…

Materials Science · Physics 2007-05-23 G. Brown , M. A. Novotny , P. A. Rikvold

In this paper we first show that any coupled system consisting of a gravitational plus a free electromagnetic field can be described geometrically in the sense that both Maxwell equations and Einstein equation having as source term the…

Mathematical Physics · Physics 2011-12-20 J. Fernando T. Giglio , Waldyr A. Rodrigues

After a synoptic panorama about some still unsolved foundational problems involving time-reversal, we show that the \emph{double time-reversal superselection rule} of Nonrelativistic Quantum Mechanics is redundant. We then analyze which,…

Quantum Physics · Physics 2007-09-17 Gavriel Segre

The conservation of the recently formulated relativistic canonical helicity [Yoshida Z, Kawazura Y, and Yokoyama T 2014 J. Math. Phys. 55 043101] is derived from Noether's theorem by constructing an action principle on the relativistic…

Plasma Physics · Physics 2015-11-05 Yohei Kawazura , Zensho Yoshida , Yasuhide Fukumoto

The phenomenological Landau-Lifshitz-Gilbert (LLG) equation of motion remains as the cornerstone of contemporary magnetisation dynamics studies, wherein the Gilbert damping parameter has been attributed to first-order relativistic effects.…

Other Condensed Matter · Physics 2018-06-28 Ritwik Mondal , Marco Berritta , Peter M. Oppeneer

We develop a complete relativistic theory to describe the dynamics of electronic angular momentum including both spin (S) and orbital (L) contributions in magnetic systems. We start with the relativistic Dirac-Kohn-Sham Hamiltonian under…

Other Condensed Matter · Physics 2026-05-19 Subhadip Santra , Ritwik Mondal , Marco Berritta , Peter M. Oppeneer

The Noether theorem connecting symmetries and conservation laws can be applied directly in a Hamiltonian framework without using any intermediate Lagrangian formulation. This requires a careful discussion about the invariance of the…

General Physics · Physics 2016-06-14 Amaury Mouchet

The aim of the paper is to study some dynamic aspects coming from a tangent form, i.e. a time dependent differential form on a tangent bundle. The action on curves of a tangent form is natural associated with that of a second order…

Mathematical Physics · Physics 2014-10-09 Paul Popescu

A Lagrangian relativistic approach to the non--linear dynamics of cosmological perturbations of an irrotational collisionless fluid is considered. Solutions are given at second order in perturbation theory for the relevant fluid and…

Astrophysics · Physics 2015-06-24 S. Matarrese , O. Pantano , D. Saez

We consider a kinetic model of self-propelled particles with alignment interaction and with precession about the alignment direction. We derive a hydrodynamic system for the local density and velocity orientation of the particles. The…

Mathematical Physics · Physics 2014-04-08 Pierre Degond , Jian-Guo Liu

We propose classical equations of motion for a charged particle with magnetic moment, taking radiation reaction into account. This generalizes the Landau-Lifshitz equations for the spinless case. In the special case of spin-polarized motion…

High Energy Physics - Theory · Physics 2012-07-05 Arnab Kar , S. G. Rajeev

Here we derive the relativistic resistive dissipative second-order magnetohydrodynamic evolution equations using the Boltzmann equation, thus extending our work from the previous paper…

Nuclear Theory · Physics 2021-09-27 Ankit Kumar Panda , Ashutosh Dash , Rajesh Biswas , Victor Roy

The Landau--Lifshitz equation describes the dynamics of magnetization inside a ferromagnet. This equation is nonlinear and has an infinite number of stable equilibria. It is desirable to control the system from one equilibrium to another. A…

Optimization and Control · Mathematics 2015-09-29 Amenda Chow , Kirsten A. Morris

We extend a recent formulation of quantum continuum mechanics [J. Tao et. al, Phys. Rev. Lett. {\bf 103}, 086401 (2009)] to many-body systems subjected to a magnetic field. To accomplish this, we propose a modified Lagrangian approach, in…

Strongly Correlated Electrons · Physics 2012-04-27 S. Pittalis , G. Vignale , I. V. Tokatly

We study the well-posedness theory for the linearized free boundary problem of incompressible ideal magnetohydrodynamics equations in a bounded domain. We express the magnetic field in terms of the velocity field and the deformation tensors…

Analysis of PDEs · Mathematics 2021-08-27 Chengchun Hao , Tao Luo

Within the framework of the effective field theory approach to the post-Newtonian approximation to General Relativity, we report the so far missing G^3 and G^4 sectors of the conservative two body dynamics at fourth perturbative order for…

General Relativity and Quantum Cosmology · Physics 2019-08-06 Stefano Foffa , Riccardo Sturani

For a one-dimensional conservative systems with position depending mass, one deduces consistently a constant of motion, a Lagrangian, and a Hamiltonian for the non relativistic case. With these functions, one shows the trajectories on the…

Classical Physics · Physics 2014-04-11 Gustavo V. Lopez , Carlos Martinez-Prieto

On the basis of gauge principle in the field theory, a new variational formulation is presented for flows of an ideal fluid. The fluid is defined thermodynamically by mass density and entropy density, and its flow fields are characterized…

Chaotic Dynamics · Physics 2007-10-12 Tsutomu Kambe