Stagnation analysis of DGMRES.
The authors study the following problem: The class of problems for which the DGMRES algorithm, when started with the initial guess \(x^{(0)} = 0\) and using exact arithmetic, computes \(m\) iterates \(x^{(1)}=\ldots=x^{(m)}=0\) without making any progress at all. Problems of dimension two and index one are solved explicitly. This results are partially extended to higher dimensions for a class of eigenvector matrices.
scientific article; zbMATH DE number 2062682