Spectrum analysis of a more general augmentation block preconditioner for generalized saddle point matrices

Abstract

In this paper, some errors are pointed out and the correct results are given for the paper Axelsson et al. (J Comput Appl Math 280:141–157, 2015). Then, a class of general augmentation block preconditioners for solving generalized saddle point systems with singular (1, 1) blocks are considered. Results concerning the eigenvalue distribution and forms of the eigenvectors of the preconditioned generalized saddle point matrix are presented. These results extend previous one in the literature.