Title
Global superconvergence of simplified hybrid combinations for elliptic equations with singularities, I. Basic theorem
Abstract
To solve the elliptic boundary value problems with singularities, the simplified hybrid combinations of the Ritz-Galerkin and finite element methods (RGM-FEM) are explored to lead to the global superconvergence rates on the entire solution domain, based on an a posteriori interpolation techniques of Lin and Yan [12] that only cost a little more computation. Let the solution domain S=S1&#63S2&#63&#1110 and S1&#55S2=&#203. Suppose that S1 can be partitioned into quasiuniform rectangles: S1=&#126ij&#143ij, a singular point occurs at &#145S2, and the singular functions are chosen in S2. Then for bilinear elements, it is proven that the simplified hybrid combinations of RGM-FEM can provide the global superconvergence rate O(h2) for solution gradients over the entire subdomains S1 and S2, where h is the maximal boundary length of &#143ij. The global superconvergence O(h2) is better, compared to O(h2&#109&#105), 0&#105&#1281 given in [4, 9]. Note that numerical stability of the simplified hybrid combinations of RGM-FEM is also optimal [6]. This paper presents the important results for the general case of Poisson-problems on a polygonal domain S estimates for the Sobolev norm ||·||1, given in a much more general sense than known before, cf. [1-4, 14-18].
Year
DOI
Venue
2000
10.1007/s006070050011
Computing
Keywords
Field
DocType
AMS Subject Classifications: 65N10,65N30.,Key Words: Elliptic equation,singularity problem,superconvergence,combined method.
Discretization,Mathematical optimization,Mathematical analysis,A priori and a posteriori,Superconvergence,Decomposition method (constraint satisfaction),Finite element method,Partial differential equation,Elliptic curve,Domain decomposition methods,Mathematics
Journal
Volume
Issue
ISSN
65
1
0010-485X
Citations 
PageRank 
References 
1
0.63
0
Authors
1
Name
Order
Citations
PageRank
Zi-Cai Li112518.79