Main results:
- H1-stable polynomial extension on a tetrahedron;
- H(div)-stable polynomial extension on a tetrahedron;
- stable broken H1 polynomial extension on a patch of thetrahedra;
- stable broken H(div) polynomial extension on a patch of thetrahedra;
- polynomial-degree-robust efficiency of H1-nonconforming methods;
- polynomial-degree-robust efficiency of H(div)-nonconforming methods.
Details: paper (preprint) with Alexandre Ern and presentation.