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arXiv 1702.01707math.NAcs.NAmath.AP
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一种用于求解非线性扩散方程的拉格朗日方案,使用移动单纯形网格

A Lagrangian scheme for the solution of nonlinear diffusion equations using moving simplex meshes

Imperial College London(帝国理工学院);University of Sussex(萨塞克斯大学);Technische Universität München(慕尼黑工业大学)

José A. Carrillo, Bertram Düring, Daniel Matthes, David S. McCormick

AI总结:

本文提出了一种拉格朗日数值方案,用于求解非线性退化福克-计划克方程,适用于多种非线性扩散方程,通过梯度流结构实现能量估计,确保解的弱紧致性。

摘要:

本文提出了一种用于求解非线性退化福克-计划克方程的拉格朗日数值方案,适用于空间维度d≥2的大量非线性扩散方程,其动力学由内部能量和给定的外部势能驱动,例如孔隙介质方程和快速扩散方程。我们方法的关键成分是动力学的梯度流结构。对于拉格朗日映射的离散化,我们使用空间中的有限线性映射子空间和时间中的变分隐式欧拉方法。由于这种时间离散化,完全离散的解继承了原始梯度流的能量估计,这些估计导致在连续极限下轨迹的弱紧致性。在二维平面情况下分析了相容性。孔隙介质方程的多种数值实验表明,该方案适合跟踪解的支持域的增长。

英文摘要:

A Lagrangian numerical scheme for solving nonlinear degenerate Fokker-Planck equations in space dimensions $d\ge2$ is presented. It applies to a large class of nonlinear diffusion equations, whose dynamics are driven by internal energies and given external potentials, e.g. the porous medium equation and the fast diffusion equation. The key ingredient in our approach is the gradient flow structure of the dynamics. For discretization of the Lagrangian map, we use a finite subspace of linear maps in space and a variational form of the implicit Euler method in time. Thanks to that time discretisation, the fully discrete solution inherits energy estimates from the original gradient flow, and these lead to weak compactness of the trajectories in the continuous limit. Consistency is analyzed in the planar situation, $d=2$. A variety of numerical experiments for the porous medium equation indicates that the scheme is well-adapted to track the growth of the solution's support.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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