子空间扩展算法及其应用  

AN AUGM ENTED SUBSPACE METHOD AND ITS APPLICATIONS

作　　者：谢和虎[1,2] Xie Hehu(LSEC,NCMIS,Institute of Computational Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,China;School of Mathematical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院数学与系统科学研究院,计算数学研究所,国家数学与交叉科学中心,科学与工程计算国家重点实验室,北京100190 [2]中国科学院大学数学科学学院,北京100049

出　　处：《数值计算与计算机应用》2020年第3期169-191,共23页Journal on Numerical Methods and Computer Applications

基　　金：国家重点研发计划项目(2019YFA0709601);科学挑战计划(TZ2016002);国家自然科学基金(11771434,91730302)资助。

摘　　要：科学研究与工程实际中存在着大量的非线性偏微分方程,这使得非线性方程的求解变得越来越重要.本综述论文利用定义在粗网格上的有限元空间来重建任意有限元函数的Aubin-Nitsche技巧的误差估计.然后介绍如何利用这种对Aubin-Nitsche技巧的新视角来设计求解半线性椭圆方程和特征值问题的扩展子空间算法,同时给出相应的收敛性分析和计算量估计.特别地,当求解多项式形式的非线性方程和特征值问题的时候,扩展子空间算法的渐进计算量可以达到最优.本文的论述表明扩展子空间算法是一种用来设计求解非线性方程快速算法的框架,可以应用于更广泛的非线性方程的求解,同时也可以结合各种高效的线性解法器来提高非线性方程的求解效率.There exist plenty of nonlinear partial differential equations in scientific research and practical engineer,which leads to the importance of numerical methods for nonlinear problems.This review paper introduces a method to build the Aubin-Nitsche estimate based on a low dimensional finite element space defined on a coarse mesh.Based on this new understanding of Aubin-Nitsche technique,an augmented subspace method is designed for semilienar elliptic equations and eigenvalue problems.The corresponding convergence analysis and estimates of computational work are provided to validate the efficiency of the presented method.Especially,the augmented subspace method gives absolutely and nonlinear independently optimal computational work for polynomial types of nonlinear partial differential equations and eigenvalue problems.This paper also shows that the augmented subspace method provides a framework to design efficient nonlinear solvers for general nonlinear equations.

关 键 词：扩展子空间算法 有限元方法 半线性椭圆方程 特征值问题 渐近计算量绝对最优 

分 类 号：O241.82[理学—计算数学]