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arXiv 1803.03437math.NAcs.NA
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用于分数波问题的空间-时间有限元方法

A space-time finite element method for fractional wave problems

School of Mathematics, Sichuan University(四川大学数学学院)

Binjie Li, Hao Luo, Xiaoping Xie

AI总结:

本文提出一种用于分数波问题的空间-时间有限元方法,采用Petrov-Galerkin型时间步进方案离散时间分数导数,证明方法稳定性并推导最优收敛性,讨论解在t=0处奇异时的性能,并通过数值实验验证理论结果。

摘要:

本文分析了一种用于分数波问题的空间-时间有限元方法。该方法采用Petrov-Galerkin型时间步进方案离散时间分数导数,证明了该方法的稳定性,并在$ H^1(0,T;L^2(Ω)) $-范数下推导出最优收敛性,在离散的$ L^\infty(0,T;H_0^1(Ω)) $-范数下推导出次优收敛性。此外,我们讨论了当解在$ t=0 $处存在奇异性时该方法的性能,并通过使用时间离散中的分级网格,证明在$ H^1(0,T;L^2(Ω)) $-范数下仍能获得最优收敛率。最后,通过数值实验验证了理论结果。

英文摘要:

This paper analyzes a space-time finite element method for fractional wave problems. The method uses a Petrov-Galerkin type time-stepping scheme to discretize the time fractional derivative of order $ γ$ ($1<γ<2$). We establish the stability of this method, and derive the optimal convergence in the $ H^1(0,T;L^2(Ω)) $-norm and suboptimal convergence in the discrete $ L^\infty(0,T;H_0^1(Ω)) $-norm. Furthermore, we discuss the performance of this method in the case that the solution has singularity at $ t= 0 $, and show that optimal convergence rate with respect to the $ H^1(0,T;L^2(Ω)) $-norm can still be achieved by using graded grids in the time discretization. Finally, numerical experiments are performed to verify the theoretical results.

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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