English
Related papers

Related papers: Momentum conservation in dissipationless reduced-f…

200 papers

When waves damp or amplify on resonant particles in a plasma, the nonresonant particles experience a recoil force that conserves the total momentum between the particles and electromagnetic fields. This force is important to understand, as…

Plasma Physics · Physics 2023-02-23 I. E. Ochs , N. J. Fisch

Linear and angular momenta of a soliton in a ferromagnet are commonly derived through the application of Noether's theorem. We show that these quantities exhibit unphysical behavior: they depend on the choice of a gauge potential in the…

Mesoscale and Nanoscale Physics · Physics 2015-10-12 Oleg Tchernyshyov

The nonlinear partial differential equations describing the spin dynamics of Heisenberg ferro and antiferromagnet are studied by Lie transformation group method. The generators of the admitted variational Lie symmetry groups are derived and…

Statistical Mechanics · Physics 2009-11-10 R. F. Egorov , I. G. Bostrem , A. S. Ovchinnikov

In a non-commutative field theory, the energy-momentum tensor obtained from the Noether method needs not be symmetric; in a massless theory, it needs not be traceless either. In a non-commutative scalar field theory, the method yields a…

High Energy Physics - Theory · Physics 2009-11-07 Mohab Abou-Zeid , Harald Dorn

We derive a Noether current for the Eulerian variational principle of ideal non-barotropic magnetohydrodynamics (MHD). It was shown previously that ideal non-barotropic MHD is mathematically equivalent to a five function field theory with…

Fluid Dynamics · Physics 2020-12-03 Asher Yahalom , Hong Qin

We present a novel method for guaranteeing linear momentum in learned physics simulations. Unlike existing methods, we enforce conservation of momentum with a hard constraint, which we realize via antisymmetrical continuous convolutional…

Machine Learning · Computer Science 2022-11-03 Lukas Prantl , Benjamin Ummenhofer , Vladlen Koltun , Nils Thuerey

A covariant formula for conserved currents of energy, momentum and angular-momentum is derived from a general form of Noethers theorem applied directly to the Einstein-Hilbert action of classical general relativity. Energy conservation in a…

General Relativity and Quantum Cosmology · Physics 2008-02-03 Philip E. Gibbs

The (static) energy momentum tensor, angular momentum tensor and scaling flux vector of micropolar elasticity are derived within the framework of Noether's theorem on variational principles. Certain balance (or broken conservation) laws of…

Materials Science · Physics 2015-12-02 Markus Lazar , Helmut O. K. Kirchner

It's well known that Noether symmetries lead to the conservation laws. Conserved quantities are constructed out of generator of the symmetry - invariant Hamiltonian vector field. Considering more general class of vector fields -…

Mathematical Physics · Physics 2016-09-07 George Chavchanidze

Observations and numerical simulations of laboratory and space plasmas in almost collisionless regimes reveal anisotropic and non-gyrotropic particle distribution functions. We investigate how such states can persist in the presence of a…

Plasma Physics · Physics 2015-08-19 S. S. Cerri , F. Pegoraro , F. Califano , D. Del Sarto , F. Jenko

Reduced fluid models including electron inertia and ion finite Larmor radius corrections are derived asymptotically, both from fluid basic equations and from a gyrofluid model. They apply to collisionless plasmas with small ion-to-electron…

Plasma Physics · Physics 2022-02-02 Thierry Passot , Pierre-Louis Sulem , Emanuele Tassi

Local symmetry transformations play an important role for establishing the existence and form of a conserved (Noether) current in systems with a global continuous symmetry. We explain how this fact leads to the existence of linear relations…

High Energy Physics - Theory · Physics 2020-02-07 Tomas Brauner

Gyrokinetic theory is arguably the most important tool for numerical studies of transport physics in magnetized plasmas. However, exact local energy-momentum conservation law for the electromagnetic gyrokinetic system has not been found…

Plasma Physics · Physics 2021-09-22 Peifeng Fan , Hong Qin , Jianyuan Xiao

We present a variational approach for relativistic ideal hydrodynamics interacting with electromagnetic fields. The momentum of fluid is introduced as the canonical conjugate variable of the position of a fluid element, which coincides with…

High Energy Physics - Theory · Physics 2015-05-20 J. H. Gaspar Elsas , T. Koide , T. Kodama

We derive the equations of motion of relativistic, non-resistive, second-order dissipative magnetohydrodynamics from the Boltzmann equation using the method of moments. We assume the fluid to be composed of a single type of point-like…

This letter reports on a metriplectic formulation of collisional, nonlinear full-$f$ electromagnetic gyrokinetic theory compliant with energy conservation and monotonic entropy production. In an axisymmetric background magnetic field, the…

Plasma Physics · Physics 2022-07-06 Eero Hirvijoki , Joshua W. Burby , Alain J. Brizard

In the variational principle leading to the Euler equation for a perfect fluid, we can use the method of undetermined multiplier for holonomic constraints representing mass conservation and adiabatic condition. For a dissipative fluid, the…

Fluid Dynamics · Physics 2012-06-03 Hiroki Fukagawa , Youhei Fujitani

The conditions of existence of extra mass flux in single component dissipative non-relativistic fluids are clarified. By considering Galilean invariance we show that if total mass flux is equal to total momentum density, then mass,…

Fluid Dynamics · Physics 2017-04-11 Peter Ván , Michal Pavelka , Miroslav Grmela

We develop a flux-conservative formalism for a Newtonian multi-fluid system, including dissipation and entrainment (i.e. allowing the momentum of one fluid to be a linear combination of the velocities of all fluids). Maximum use is made of…

Fluid Dynamics · Physics 2016-09-08 Nils Andersson , G. L. Comer

The Eulerian variational principle for the Vlasov-Poisson-Amp\`{e}re system of equations in a general coordinate system is presented. The invariance of the action integral under an arbitrary spatial coordinate transformation is used to…

Plasma Physics · Physics 2018-11-14 H. Sugama , M. Nunami , S. Satake , T. -H. Watanabe