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arXiv 1902.02764math.AP
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用坐标变换求解具有退化快衰减迁移率的非线性扩散方程

Nonlinear diffusion equations with degenerate fast-decay mobility by coordinate transformation

N. Ansini, S. Fagioli

摘要:

本文证明了在有界区间上具有退化迁移率的非线性扩散方程在一定密度$u$下解的存在唯一性.对于\emph{fast-decay}迁移率,即迁移率函数满足Osgood可积性条件的情形,引入适当的坐标变换,得到了一个新的具有线性迁移率的非线性扩散方程.我们观察到,坐标变换诱导的密度和非线性,所描述的原始非线性流动性的质量保持标度,包括在扩散过程中。我们证明了重标密度$ρ$是具有线性迁移率的非线性扩散方程的唯一弱解.此外,密度$ρ$得到的结果使我们能够激发上述变量变换,并在不规定任何边界条件的情况下,以原始密度$u$的形式陈述结果。

英文摘要:

We prove an existence and uniqueness result for solutions to nonlinear diffusion equations with degenerate mobility posed on a bounded interval for a certain density $u$. In case of \emph{fast-decay} mobilities, namely mobilities functions under a Osgood integrability condition, a suitable coordinate transformation is introduced and a new nonlinear diffusion equation with linear mobility is obtained. We observe that the coordinate transformation induces a mass-preserving scaling on the density and the nonlinearity, described by the original nonlinear mobility, is included in the diffusive process. We show that the rescaled density $ρ$ is the unique weak solution to the nonlinear diffusion equation with linear mobility. Moreover, the results obtained for the density $ρ$ allow us to motivate the aforementioned change of variable and to state the results in terms of the original density $u$ without prescribing any boundary conditions.

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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