Guaranteed and robust error bounds for nonconforming approximations of elliptic problems
Guaranteed and robust error bounds for nonconforming approximations of elliptic problems
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DOI:
10.1093/imanum/drp037
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发表时间:
2011-04
影响因子:
2.1
通讯作者:
S. Repin;S. Tomar
中科院分区:
文献类型:
--
作者:
S. Repin;S. Tomar
We present guaranteed, robust and computable a posteriori error estimates for nonconforming approximations of elliptic problems. Our analysis is based on a Helmholtz-type decomposition of the error expressed in terms of fluxes. Such a decomposition results in a gradient term and a divergence-free term, that are the exact solutions of two auxiliary problems. We suggest a new approach to deriving computable two-sided bounds of the norms of these solutions. The a posteriori estimates obtained in this paper differ from those that are based on projections of nonconforming approximations to a conforming space. Numerical experiments confirm that these new estimates provide very accurate error bounds, and can be efficiently exploited in practical computations.