Summary. Some observations are made on abstract error estimates for Galerkin approximations based on Babuška-Brezzi conditions. A basic error estimate due to Babuška is sharpened by means of an identity that \(\| P\|=\|I-P \|\) for any nontrivial idempotent operator P. Some remarks are also made on the Brezzi's theory for mixed variational problems and their Galerkin approximations.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received March 1, 2000 / Revised version received September 28, 2000 / Published online June 17, 2002
RID="*"
ID="*" This work was partially supported by NSF DMS-9706949, NSF ACI-9800244 and NASA NAG2-1236
Correspondence to: J. Xu
Rights and permissions
About this article
Cite this article
Xu, J., Zikatanov, L. Some observations on Babu\vs}ka and Brezzi theories. Numer. Math. 94, 195–202 (2003). https://doi.org/10.1007/s002110100308
Issue Date:
DOI: https://doi.org/10.1007/s002110100308