2022/06/27 by Bradley, Susanne, Greif, Chen
#FOS: Mathematics #Numerical Analysis (math.NA)
paper · doi:10.48550/arxiv.2206.13624
We consider the iterative solution of symmetric saddle-point matrices with a singular leading block. We develop a new ideal positive definite block diagonal preconditioner that yields a preconditioned operator with four distinct eigenvalues. We offer a few techniques for making the preconditioner practical, and illustrate the effectiveness of our approach with numerical experiments.