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arXiv 2208.01792math.AP
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多孔介质方程和反应扩散方程组的拉格朗日解

Lagrangian solutions to the Porous Media Equation and Reaction Diffusion Systems

Matt Jacobs

摘要:

在本文中,我们构造了沿多孔介质方程的弱解产生的压力梯度的全局时间正向和反向拉格朗日流映射。主要的困难是,当初始数据具有紧支撑时,众所周知,压力梯度不是BV函数。因此,正则拉格朗日流的理论不能应用于构造流图。为了克服这个困难,我们开发了一个新的参数,结合Aronson-Bénilan型估计与Crippa和De Lellis的定量拉格朗日流理论,以表明某些衡量流图稳定性的双对数量不会迅速膨胀到足以阻止紧致性。我们的论点是足够灵活的处理Hele-Shaw极限和多孔介质方程的多物种的推广,该方程是由一个耦合的双曲抛物系统的反应扩散方程取代。作为我们的流程图的一个应用,我们能够构建不同物种不能混合在一起的解决方案,如果他们在初始时间被分离。

英文摘要:

In this paper, we construct global-in-time forward and backward Lagrangian flow maps along the pressure gradient generated by weak solutions of the Porous Media Equation. The main difficulty is that when the initial data has compact support, it is well-known that the pressure gradient is not a BV function. Thus, the theory of regular Lagrangian flows cannot be applied to construct the flow maps. To overcome this difficulty, we develop a new argument that combines Aronson-Bénilan type estimates with the quantitative Lagrangian flow theory of Crippa and De Lellis to show that certain doubly logarithmic quantities measuring the stability of flow maps do not blow up fast enough to prevent compactness. Our arguments are sufficiently flexible to handle the Hele-Shaw limit and a multispecies generalization of the Porous Media Equation where the equation is replaced by a coupled hyperbolic-parabolic system of reaction diffusion equations. As one application of our flow maps, we are able to construct solutions where different species cannot mix together if they were separated at initial time.

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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