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Time-evolving perforated domains arise in many engineering and geoscientific applications, including reactive transport, particle deposition, and structural degradation in porous media. Accurately capturing the macroscopic behavior of such…

Numerical Analysis · Mathematics 2025-06-27 Wei Xie , Viet Ha Hoang , Yin Yang , Yunqing Huang

In this paper we develop magnetic induction conforming multiscale formulations for magnetoquasistatic problems involving periodic materials. The formulations are derived using the periodic homogenization theory and applied within a…

Numerical Analysis · Mathematics 2017-09-21 Innocent Niyonzima , Ruth V. Sabariego , Patrick Dular , Kevin Jacques , Christophe Geuzaine

In this paper, a methodology for fine scale modeling of large scale structures is proposed, which combines the variational multiscale method, domain decomposition and model order reduction. The influence of the fine scale on the coarse…

Computational Engineering, Finance, and Science · Computer Science 2023-07-06 Philipp Diercks , Karen Veroy , Annika Robens-Radermacher , Jörg F. Unger

In this letter, we provide a microscopic model for the ultrafast remagnetization of atomic moments already quenched above Stoner-Curie temperature by a strong laser fluence. Combining first principles density functional theory, atomistic…

Materials Science · Physics 2015-06-11 Raghuveer Chimata , Anders Bergman , Lars Bergqvist , Biplab Sanyal , Olle Eriksson

A second order accurate numerical scheme is proposed and implemented for the Landau-Lifshitz-Gilbert equation, which models magnetization dynamics in ferromagnetic materials, with large damping parameters. The main advantages of this method…

Computational Physics · Physics 2022-01-26 Yongyong Cai , Jingrun Chen , Cheng Wang , Changjian Xie

We consider the numerical approximation of the inertial Landau-Lifshitz-Gilbert equation (iLLG), which describes the dynamics of the magnetization in ferromagnetic materials at subpicosecond time scales. We propose and analyze two fully…

Numerical Analysis · Mathematics 2021-10-07 Michele Ruggeri

A general technique is outlined for investigating supersymmetry properties of a charged spin-$\half$ quantum particle in time-varying electromagnetic fields. The case of a time-varying uniform magnetic induction is examined and shown to…

High Energy Physics - Theory · Physics 2009-09-25 V. Alan Kostelecký , V. I. Man'ko , Michael Martin Nieto , D. Rodney Truax

The macroscopic properties of materials that we observe and exploit in engineering application result from complex interactions between physics at multiple length and time scales: electronic, atomistic, defects, domains etc. Multiscale…

This paper concerns the analysis of a multiscale method for wave propagation problems in microscopically nonhomogeneous media. A direct numerical approximation of such problems is prohibitively expensive as it requires resolving the…

Numerical Analysis · Mathematics 2017-02-20 Doghonay Arjmand , Olof Runborg

The separation between molecular and mesoscopic length and time scales poses a severe limit to molecular simulations of mesoscale phenomena. We describe a hybrid multiscale computational technique which address this problem by keeping the…

Fluid Dynamics · Physics 2009-11-13 G. De Fabritiis , R. Delgado-Buscalioni , P. V. Coveney

Numerical integration of a stochastic Landau-Lifshitz-Gilbert equation is used to study dynamic processes in single-domain nanoscale magnets at nonzero temperatures. Special attention is given to including thermal fluctuations as a Langevin…

Materials Science · Physics 2009-10-31 Gregory Brown , M. A. Novotny , Per Arne Rikvold

The dynamics of real magnets is often governed by several interacting processes taking place simultaneously at different length scales. For dynamical simulations the relevant length scales should be coupled, and the energy transfer…

Materials Science · Physics 2007-05-23 V. V. Dobrovitski , M. I. Katsnelson , B. N. Harmon

This article addresses a problem of micromagnetics: the reversal of magnetic moments in layered spring magnets. A one-dimensional model is used of a film consisting of several atomic layers of a soft material on top of several atomic layers…

Dynamical Systems · Mathematics 2025-10-20 J. Samuel Jiang , Hans G. Kaper , Gary K. Leaf

In this paper, we propose a variationally consistent technique for decreasing the maximum eigenfrequencies of structural dynamics related finite element formulations. Our approach is based on adding a symmetric positive-definite term to the…

Numerical Analysis · Mathematics 2022-07-27 Stein K. F. Stoter , Thi-Hoa Nguyen , René R. Hiemstra , Dominik Schillinger

We formulated a technique which combines the first-principles, micromagnetic and microstructural calculations and allows us to study the nature of hysteretic phenomena in hard magnets. Two distinct sources of coercivity in polytwinned CoPt…

Materials Science · Physics 2009-11-07 K. D. Belashchenko , V. P. Antropov

Magnetic materials host a wealth of nonlinear dynamics, textures, and topological defects. This is possible due to the competition between strong nonlinearity and dispersion that act at the atomic scale as well as long-range interactions.…

Mesoscale and Nanoscale Physics · Physics 2024-07-02 Kyle Rockwell , Joel Hirst , Thomas A. Ostler , Ezio Iacocca

We establish a machine learning model for the prediction of the magnetization dynamics as function of the external field described by the Landau-Lifschitz-Gilbert equation, the partial differential equation of motion in micromagnetism. The…

Computational Physics · Physics 2021-07-27 Lukas Exl , Norbert J. Mauser , Sebastian Schaffer , Thomas Schrefl , Dieter Suess

In this paper, a nonlinear system of fractional ordinary differential equations with multiple scales in time is investigated. We are interested in the effective long-term computation of the solution. The main challenge is how to obtain the…

Numerical Analysis · Mathematics 2022-01-07 Zhaoyang Wang , Ping Lin

A phase diagram of the magnetization dynamics is studied by numerically solving the Landau-Lifshitz-Gilbert (LLG) equation in a spin torque oscillator consisting of asymmetric two free layers that are magnetized in in-plane direction. We…

Mesoscale and Nanoscale Physics · Physics 2019-04-19 Tomohiro Taniguchi

In this paper, we consider a parabolic problem with time-dependent heterogeneous coefficients. Many applied problems have coupled space and time heterogeneities. Their homogenization or upscaling requires cell problems that are formulated…

Numerical Analysis · Mathematics 2021-06-24 Jiuhua Hu , Wing Tat Leung , Eric Chung , Yalchin Efendiev , Sai-Mang Pun