Hierarchical bases of finite-element spaces in the discretization of nonsymmetric elliptic boundary value problems

In the case of symmetric and positive definite plane elliptic boundary value problems, the condition numbers of the stiffness matrices arising from finite element discretizations grow only quadratically with the number of refinement levels, if one uses hierarchical bases of the finite element spaces instead of the usual nodal bases; see [9]. Here we show that results of the same type hold for nonsymmetric problems and we describe the interesting consequences for the solution of the discretized problems by Krylov-space methods.