Subgrid stabilization of Galerkin approximations of linear monotone operators

This paper presents a stabilized Galerkin technique for approximating monot one linear operators in a Hilbert space. The key idea consists in introduci ng an approximation space that is broken up into resolved scales and subgri d scales so that the bilinear form associated with the problem satisfies a uniform inf-sup condition with respect to this decomposition. An optimal Ga lerkin approximation is obtained by introducing an artificial diffusion on the subgrid scales.