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arXiv 2408.07396math.AP
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交叉扩散方程组中非局部Cahn-Hilliard项的存在性与局部渐进行为

Existence and local asymptotics for a system of cross-diffusion equations with nonlocal Cahn-Hilliard terms

Elisa Davoli, Greta Marino, Jan-Frederik Pietschmann, Nicola Zamponi

AI总结:

本文研究了一种包含交叉扩散效应和退化迁移率的多组分混合物非局部Cahn-Hilliard模型,通过定义适合可能退化情况的弱解概念,证明了全局时间内的存在性,并利用梯度流结构和熵有界方法的扩展,结合辅助变分问题的细致分析,获得近似时间离散系统的解,最终证明此类非局部Cahn-Hilliard方程组的解收敛到局部解。

摘要:

我们研究了一种多组分混合物的非局部Cahn-Hilliard模型,包含交叉扩散效应和退化迁移率。非局部性通过对称奇异核来描述。我们定义了一个适合可能退化的弱解概念,并证明了其全局时间内的存在性。证明依赖于应用系统的正式梯度流结构(以克服缺乏先验估计),结合熵有界方法的扩展,后者涉及对辅助变分问题的细致分析。这使得能够获得近似时间离散系统的解。让时间步长趋于零,我们恢复了所需的非局部弱解,其中由于低正则性,Cahn-Hilliard项需要特殊处理。最后,我们证明了此类非局部Cahn-Hilliard方程组的解对局部解的收敛性。

英文摘要:

We study a nonlocal Cahn-Hilliard model for a multicomponent mixture with cross-diffusion effects and degenerate mobility. The nonlocality is described by means of a symmetric singular kernel. We define a notion of weak solution adapted to possible degeneracies and prove, as our first main result, its global-in-time existence. The proof relies on an application of the formal gradient flow structure of the system (to overcome the lack of a priori estimates), combined with an extension of the boundedness-by-entropy method, involving a careful analysis of an auxiliary variational problem. This allows to obtain solutions to an approximate, time-discrete system. Letting the time step size go to zero, we recover the desired nonlocal weak solution where, due to their low regularity, the Cahn-Hilliard terms require a special treatment. Finally, we prove convergence of solutions for this class of nonlocal Cahn-Hilliard equations to their local counterparts.

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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