High-order local rate of convergence by mesh-refinement in the finite element method

Author:

Eriksson Kenneth

Abstract

We seek approximations of the solution u of the Neumann problem for the equation L u = f Lu = f in Ω \Omega with special emphasis on high-order accuracy at a given point x 0 Ω ¯ {x_0} \in \bar \Omega . Here Ω \Omega is a bounded domain in R N ( N 2 ) {R^N}(N \geqslant 2) with smooth boundary, and L is a second-order, uniformly elliptic, differential operator with smooth coefficients. An approximate solution u h {u_h} is determined by the standard Galerkin method in a space of continuous piecewise polynomials of degree at most r 1 r - 1 on a partition Δ h ( x 0 , α ) {\Delta _h}({x_0},\alpha ) of Ω \Omega . Here h is a global mesh-size parameter, and α \alpha is the degree of a certain systematic refinement of the mesh around the given point x 0 {x_0} , where larger α \alpha ’s mean finer mesh, and α = 0 \alpha = 0 corresponds to the quasi-uniform case with no refinement. It is proved that, for suitable (sufficiently large) α \alpha ’s the high-order error estimate ( u u h ) ( x 0 ) = O ( h 2 r 2 ) (u - {u_h})({x_0}) = O({h^{2r - 2}}) holds. A corresponding estimate with the same order of convergence is obtained for the first-order derivatives of u u h u - {u_h} . These estimates are sharp in the sense that the required degree of refinement in each case is essentially the same as is needed for the local approximation to this order near x 0 {x_0} . For the estimates to hold, it is sufficient that the exact solution u have derivatives to the rth order which are bounded close to x 0 {x_0} and square integrable in the rest of Ω \Omega . The proof of this uses high-order negative-norm estimates of u u h u - {u_h} . The number of elements in the considered partitions is of the same order as in the corresponding quasi-uniform ones. Applications of the results to other types of boundary value problems are indicated.

Publisher

American Mathematical Society (AMS)

Subject

Applied Mathematics,Computational Mathematics,Algebra and Number Theory

Reference20 articles.

Cited by 5 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. Singularities and treatments of elliptic boundary value problems;Mathematical and Computer Modelling;2000-04

2. On Adaptive Finite Element Methods for Fredholm Integral Equations of the Second Kind;SIAM Journal on Numerical Analysis;1994-06

3. Local behavior in finite element methods;Finite Element Methods (Part 1);1991

4. Basic error estimates for elliptic problems;Finite Element Methods (Part 1);1991

5. Quality assessment and control of finite element solutions;Finite Elements in Analysis and Design;1987-04

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3