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arXiv 2104.15048math.NAcs.NAmath.DS
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网络上偏微分方程的谱解

Spectral solutions of PDEs on networks

M. Brio, J. -G. Caputo, H. Kravitz

摘要:

为了解决线性偏微分方程的度量图与标准的耦合条件(连续性和基尔霍夫定律),我们开发和比较的频谱,二阶有限差分,和不连续Galerkin方法。谱方法以机器精度产生任意阶的特征值和特征向量,并指数收敛。这些特征向量提供了一个类似傅立叶的基础上扩展的解决方案;然而,更复杂的耦合条件需要额外的研究。间断伽辽金法提供了任意多项式阶的近似;然而,精确计算高阶特征值需要相应的特征向量得到很好的解析。该方法允许任意的非基尔霍夫通量条件,并需要在顶点处的特殊惩罚项,以强制连续的解决方案。对于有限差分法,标准单侧二阶有限差分模板将顶点解的精度降低到$ O(h^{3/2})$。为了保持整体的二阶精度,我们对每个边缘使用了鬼细胞。对于所有这三种方法,我们提供的实施细节,他们的验证,并举例说明其性能的特征值问题,泊松方程,和波动方程。

英文摘要:

To solve linear PDEs on metric graphs with standard coupling conditions (continuity and Kirchhoff's law), we develop and compare a spectral, a second-order finite difference, and a discontinuous Galerkin method. The spectral method yields eigenvalues and eigenvectors of arbitary order with machine precision and converges exponentially. These eigenvectors provide a Fourier-like basis on which to expand the solution; however, more complex coupling conditions require additional research. The discontinuous Galerkin method provides approximations of arbitrary polynomial order; however computing high-order eigenvalues accurately requires the respective eigenvector to be well-resolved. The method allows arbitrary non-Kirchhoff flux conditions and requires special penalty terms at the vertices to enforce continuity of the solutions. For the finite difference method, the standard one-sided second-order finite difference stencil reduces the accuracy of the vertex solution to $ O(h^{3/2})$. To preserve overall second-order accuracy, we used ghost cells for each edge. For all three methods we provide the implementation details, their validation, and examples illustrating their performance for the eigenproblem, Poisson equation, and the wave equation.

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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