A space-time formulation for multiscale phenomena

We develop subgrid scale models for a class of nonsymmetric, linear evolution operators by applying the variational multiscale method in space-time. The results generalize those of Hughes [14] which were confined to the steady case. The subgrid scale models are shown to be a paradigm for “bubble” function finite element methods and provide a theoretical and practical framework for the development of so-called stabilized methods.