A preconditioned iteration method for solving saddle point problems
Juan Zhang, Yiyi Luo
TL;DR
The paper tackles efficient solution of large-scale saddle point problems by introducing the PSLR preconditioner, which blends a power-series based approximate inverse of the Schur complement with a low-rank correction to avoid nested dissection. It establishes convergence criteria for the power-series approach, provides error bounds for the approximate inverse, and analyzes the computational complexity of the PSLR-GMRES framework. Through extensive numerical experiments on symmetric and asymmetric systems (including Stokes-type discretizations), the results show improved convergence rates and reduced computational effort compared to standard Krylov methods like CG, PCG, and ADI in many settings. The work demonstrates a practical, scalable approach for preconditioning saddle-point systems, with potential impact on constrained optimization and fluid dynamics simulations.
Abstract
This paper introduces a preconditioned method designed to comprehensively address the saddle point system with the aim of improving convergence efficiency. In the preprocessor construction phase, a technical approach for solving the approximate inverse matrix of sparse matrices is presented. The effectiveness of the proposed method is demonstrated through numerical examples, emphasizing its efficacy in approximating the inverse matrix. Furthermore, the preprocessing technology includes a low-rank processing step, effectively reducing algorithmic complexity. Numerical experiments validate the effectiveness and feasibility of PSLR-GMRES in solving the saddle point system.
