Analysis of a mixed finite element for the Stokes problem. II: Construction and error estimates (Q1203415)

[For part I see ibid. 62, No. 2, 149-160 (1992; reviewed above).] The authors apply the general results obtained in the first part to a mixed finite element discretization of the Stokes problem. Starting from the Hellan-Herrmann-Johnson formulation they construct a stable mixed discretization where the symmetry of the stress tensor is approximately realized by introducing an appropriate Lagrange multiplier. The derivation of optimal error estimates requires non-standard approximation spaces. This poses a certain difficulty which can partly be circumvented by hybridization leading also to the superconvergent approximation of the velocities.