Abstract
Several open questions in the numerical analysis of singularly perturbed differential equations are discussed. These include whether certain convergence results in various norms are optimal, when supercloseness is obtained in finite element solutions, the validity of defect correction in finite difference approximations, and desirable adaptive mesh refinement results that remain to be proved or disproved.
MSC: 65-02
The authors would like to thank Natalia Kopteva and Martin Schopf for helpful discussions related to this paper. We are also grateful to the referees for their careful reading of the paper and their useful comments.
Received: 2014-11-4
Revised: 2015-3-10
Accepted: 2015-4-7
Published Online: 2015-6-16
Published in Print: 2015-10-1
© 2015 by De Gruyter
