Resumen de An improved lopsided shift-splitting preconditioner for three-by-three block saddle point problems

Jun Li, Xiangtuan Xiong

• We consider an improved lopsided shift-splitting (ILSS) preconditioner for solving three- by-three block saddle point problems. This method enhances the work of Zhang et al. [Comput. Appl. Math. 41 (2022), 261]. We prove that the iteration method produced by the ILSS preconditioner is unconditionally convergent. Additionally, we show that all eigenvalues of the ILSS preconditioned matrix are real, with non-unit eigenvalues located in a positive interval. Numerical experiments demonstrate the effectiveness of the ILSS preconditioner.