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Related papers: A generalized Theory of Diffusion based on Kinetic…

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We extend to multi-dimensions the work of [1], where new fully explicit kinetic methods were built for the approximation of linear and non-linear convection-diffusion problems. The fundamental principles from the earlier work are retained:…

Numerical Analysis · Mathematics 2023-12-29 Gauthier Wissocq , Rémi Abgrall

Here, we adapt the concept of transformational thermodynamics, whereby the flux of temperature is controlled via anisotropic heterogeneous diffusivity, for the diffusion and transport of mass concentration. The n-dimensional,…

Biological Physics · Physics 2013-02-01 Sebastien Guenneau , Tania Puvirajesinghe

Kinetically-constrained models are lattice-gas models that are used for describing glassy systems. By construction, their equilibrium state is trivial and there are no equal-time correlations between the occupancy of different sites. We…

Statistical Mechanics · Physics 2017-03-01 Eial Teomy , Yair Shokef

The spin-diffusion constant of the 2D $t-J$ model is calculated for the first time using an analytical approach at high temperatures and a recently-developed numerical method based on the Lanczos technique combined with random sampling in…

Condensed Matter · Physics 2009-10-22 J. Bonca , J. Jaklic

Using classical description of spin degrees of freedom, we extend recent formulation of the perfect-fluid hydrodynamics for spin-polarized fluids to the case including dissipation. Our work is based on the analysis of classical kinetic…

We study a kinetic toy model for a spray of particles immersed in an ambient fluid, subject to some additional random forcing given by a mixing, space-dependent Markov process. Using the perturbed test function method, we derive the…

Analysis of PDEs · Mathematics 2020-05-20 Arnaud Debussche , Angelo Rosello , Julien Vovelle

Experiment has established that spin-glasses can support a steady-state spin current $\vec{j}_{i}$. However, the accepted theory of spin glass dynamics permits oscillations but no steady-state spin current. Onsager's irreversible…

Mesoscale and Nanoscale Physics · Physics 2023-04-04 Chen Sun , Wayne M. Saslow

The generalised hydrodynamic theory of an electron gas, which does not rely on an assumption of a local equilibrium, is derived as the long-wave limit of a kinetic equation. Apart from the common hydrodynamics variables the theory includes…

Soft Condensed Matter · Physics 2009-10-31 I. Tokatly , O. Pankratov

The dynamics of spin at finite temperature in the spin-1/2 Heisenberg chain was found to be superdiffusive in numerous recent numerical and experimental studies. Theoretical approaches to this problem have emphasized the role of nonabelian…

Statistical Mechanics · Physics 2022-06-20 Pieter W. Claeys , Austen Lamacraft , Jonah Herzog-Arbeitman

Metastable condensed matter typically fluctuates about local energy minima at the femtosecond time scale before transitioning between local minima after nanoseconds or microseconds. This vast scale separation limits the applicability of…

Computational Physics · Physics 2017-11-22 Brittan A Farmer , Mitchell Luskin , Petr Plecháč , Gideon Simpson

Kinetic theory provides an elegant framework for studying dispersed particles in turbulent flows. Here the application of such probability density function (PDF)-based descriptions is considered in the context of particle clustering. The…

Fluid Dynamics · Physics 2025-04-03 C. P. Stafford , D. C. Swailes , M. W. Reeks

We numerically investigate, through discrete element simulations, the steady flow of identical, frictionless spheres sheared between two parallel, bumpy planes in the absence of gravity and under a fixed normal load. We measure the spatial…

Soft Condensed Matter · Physics 2024-07-25 Dalila Vescovi , Astrid S. de Wijn , Graham L. W. Cross , Diego Berzi

Using the conservation laws for charge, energy, momentum, and angular momentum, we derive hydrodynamic equations for the charge density, local temperature, and fluid velocity, as well as for the spin tensor, starting from local equilibrium…

Nuclear Theory · Physics 2018-04-18 Wojciech Florkowski , Bengt Friman , Amaresh Jaiswal , Enrico Speranza

We develop a theoretical framework for the diffusion of a single unconstrained species of atoms on a crystal lattice that provides a generalization of the classical theories of atomic diffusion and diffusion-induced phase separation to…

Materials Science · Physics 2007-05-23 Eliot Fried , Shaun Sellers

Spin and charge-current dynamics after ultrafast spin-polarized excitation in a normal metal are studied theoretically using a wave-diffusion theory. It is shown analytically how this macroscopic approach correctly describes the ballistic…

Materials Science · Physics 2011-11-22 Steffen Kaltenborn , Yao-Hui Zhu , Hans Christian Schneider

Spin transport properties at finite electric and magnetic fields are studied by using the generalized semiclassical Boltzmann equation. It is found that the spin diffusion equation for non-equilibrium spin density and spin currents involves…

Materials Science · Physics 2009-11-07 Y. Qi , S. Zhang

We study diffusive mixing in the presence of thermal fluctuations under the assumption of large Schmidt number. In this regime we obtain a limiting equation that contains a diffusive thermal drift term with diffusion coefficient obeying a…

Statistical Mechanics · Physics 2015-06-18 A. Donev , T. G. Fai , E. Vanden-Eijnden

We present the arising of the Fick cross-diffusion system of equations for fluid mixtures from the multi-species Boltzmann in a rigorous manner in Sobolev spaces. To this end, we formally show that, in a diffusive scaling, the…

Analysis of PDEs · Mathematics 2020-03-19 Marc Briant , Bérénice Grec

Due to its parabolic character, the diffusion equation exhibits instantaneous spatial spreading, and becomes unstable when Lorentz-boosted. According to the conventional interpretation, these features reflect a fundamental incompatibility…

General Relativity and Quantum Cosmology · Physics 2026-01-28 Lorenzo Gavassino

We investigate the temperature dependence of the shear viscosity and spin diffusion in a two-dimensional Fermi gas with contact interactions, as realized in ultra-cold atomic gases. We describe the transport coefficients in terms of a…

Quantum Gases · Physics 2012-07-16 Tilman Enss , Carolin Küppersbusch , Lars Fritz