Application of block Krylov subspace algorithms to the Wilson–Dirac equation with multiple right-hand sides in lattice QCD Original Research Article

It is well known that the block Krylov subspace solvers work efficiently for some cases of the solution of differential equations with multiple right-hand sides. In lattice QCD calculation of physical quantities on a given configuration demands us to solve the Dirac equation with multiple sources. We show that a new block Krylov subspace algorithm recently proposed by the authors reduces the computational cost significantly without losing numerical accuracy for the solution of the image-improved Wilson–Dirac equation.