On a Circulant Representation of the H^(1/2) Seminorm on Rectangles
The matrix representations of the norm are efficient preconditioners for elliptic problems and boundary integral equations of first kind. A new circulant sparse matrix representation has been presented for the seminorm in the space of bilinear finite elements on a rectangular shaped surface. The matrix contains only non-zero elements where is the number of unknowns.
Keywords: Elliptic problems, domain decomposition, preconditioned conjugate gradient method.