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arXiv 1802.04658math.APcs.NAmath-phmath.MPmath.NAphysics.class-ph
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具有小参数的超奇异非线性边值问题

Hypersingular nonlinear boundary-value problems with a small parameter

Institute for Problems in Mechanics, Russian Academy of Sciences(俄罗斯科学院力学问题研究所);Bauman Moscow State Technical University(鲍曼莫斯科国立技术大学);National Research Nuclear University MEPhI(国立研究核子大学MEPhI);University of Sonora(索诺拉大学)

Andrei D. Polyanin, Inna K. Shingareva

AI总结:

本文首次描述了具有小参数ε的超奇异非线性边值问题,其边界层具有异常特性,需非线性点变换才能应用渐近展开法,且提供精确解用于数值方法验证。

摘要:

首次描述了具有小参数ε的超奇异非线性边值问题。这些问题与通常的线性和拟线性奇异扰动边值问题有本质区别,具有以下异常特性:(i) 超奇异边值问题中会出现超薄边界层,边界层导数可达到e^{1/ε}量级;(ii) 边界层位置由未知函数边界值决定;(iii) 超奇异边值问题无法直接应用匹配渐近展开法,需先进行非线性点变换。给出了ODE和PDE的超奇异非线性边值问题实例,并获得精确解。这些精确解可用于比较奇异扰动问题数值积分方法的有效性,并开发新数值和近似解析方法。

英文摘要:

For the first time, some hypersingular nonlinear boundary-value problems with a small parameter~$\varepsilon$ at the highest derivative are described. These problems essentially (qualitatively and quantitatively) differ from the usual linear and quasilinear singularly perturbed boundary-value problems and have the following unusual properties: (i) in hypersingular boundary-value problems, super thin boundary layers arise, and the derivative at the boundary layer can have very large values of the order of $e^{1/\varepsilon}$ and more (in standard problems with boundary layers, the derivative at the boundary has the order of $\varepsilon^{-1}$ or less); (ii) in hypersingular boundary-value problems, the position of the boundary layer is determined by the values of the unknown function at the boundaries (in standard problems with boundary layers, the position of the boundary layer is determined by coefficients of the given equation, and the values of the unknown function at the boundaries do not play a role here); (iii) hypersingular boundary-value problems do not admit a direct application of the method of matched asymptotic expansions (without a preliminary nonlinear point transformation of the equation under consideration). Examples of hypersingular nonlinear boundary-value problems with ODEs and PDEs are given and their exact solutions are obtained. It is important to note that the exact solutions presented in this paper can be used to compare the effectiveness of various methods of numerical integration of singularly perturbed problems with boundary layers, and also to develop new numerical and approximate analytical methods.

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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