Extension by zero in discrete trace spaces: Inverse estimates
Extension by zero in discrete trace spaces: Inverse estimates
We consider lowest-order ${\boldsymbol H}^{-\frac {1}{2}}(\operatorname {div}_\Gamma , \Gamma )$- and $H^{-\frac {1}{2}}(\Gamma )$-conforming boundary element spaces supported on part of the boundary $\Gamma$ of a Lipschitz polyhedron. Assuming families of triangular meshes created by regular refinement, we prove that on these spaces the norms of the extension by zero …