Seed methods for linear equations in lattice qcd problems with multiple right-hand sides
Abdou M. Abdel-Rehim, Ronald B. Morgan, Walter Wilcox · Proceedings of The XXVI International Symposium on Lattice Field Theory — PoS(LATTICE 2008) · 2009
We consider three improvements to seed methods for Hermitian linear systems with multiple right-hand sides: only the Krylov subspace for the first system is used for seeding subsequent right-hand sides, the first right-hand side is solved past convergence, and periodic reorthogonalization is used in order to control roundoff errors associated with the Conjugate Gradient algorithm.The method is tested for the case of Wilson fermions near kappa critical and a considerable speed up in the convergence is observed.