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.
All Science Journal Classification (ASJC) codes
- Applied Mathematics
- Computational Mathematics