44 citations · 152 across the 12 of their papers we have counts for
11 papers · 1 filter
Octet baryon isovector charges from lattice QCD
Gunnar S. Bali, Sara Collins, Simon Heybrock +4
We determine the axial, scalar and tensor isovector charges of the nucleon, sigma and cascade baryons as well as the difference between the up and down quark masses, . We…
Baryonic and mesonic 3-point functions with open spin indices
Gunnar S. Bali, Sara Collins, Benjamin Glässle +5
We have implemented a new way of computing three-point correlation functions. It is based on a factorization of the entire correlation function into two parts which are evaluated w…
Multiple right-hand-side setup for the DD-αAMG
Daniel Richtmann, Simon Heybrock, Tilo Wettig
The setup cost of a modern solver such as DD-αAMG (Wuppertal Multigrid) is a significant contribution to the total time spent on solving the Dirac equation, and in HMC it can even…
Lattice QCD with Domain Decomposition on Intel Xeon Phi Co-Processors
Simon Heybrock, Bálint Joó, Dhiraj D. Kalamkar +4
The gap between the cost of moving data and the cost of computing continues to grow, making it ever harder to design iterative solvers on extreme-scale architectures. This problem…
Double-pass variants for multi-shift BiCGstab(ell)
Simon Heybrock
In analogy to Neuberger's double-pass algorithm for the Conjugate Gradient inversion with multi-shifts we introduce a double-pass variant for BiCGstab(ell). One possible applicatio…
QPACE -- a QCD parallel computer based on Cell processors
H. Baier, H. Boettiger, M. Drochner +32
QPACE is a novel parallel computer which has been developed to be primarily used for lattice QCD simulations. The compute power is provided by the IBM PowerXCell 8i processor, an e…
A nested Krylov subspace method to compute the sign function of large complex matrices
Jacques C. R. Bloch, Simon Heybrock
We present an acceleration of the well-established Krylov-Ritz methods to compute the sign function of large complex matrices, as needed in lattice QCD simulations involving the ov…
Krylov subspace methods and the sign function: multishifts and deflation in the non-Hermitian case
Jacques C. R. Bloch, Tobias Breu, Andreas Frommer +3
Rational approximations of the matrix sign function lead to multishift methods. For non-Hermitian matrices long recurrences can cause storage problems, which can be circumvented wi…
A nested Krylov subspace method for the overlap operator
Jacques C. R. Bloch, Simon Heybrock
We present a novel method to compute the overlap Dirac operator at zero and nonzero quark chemical potential. To approximate the sign function of large, sparse matrices, standard m…
Short-recurrence Krylov subspace methods for the overlap Dirac operator at nonzero chemical potential
Jacques C. R. Bloch, Tobias Breu, Andreas Frommer +3
The overlap operator in lattice QCD requires the computation of the sign function of a matrix, which is non-Hermitian in the presence of a quark chemical potential. In previous wor…
Status of the QPACE Project
H. Baier, H. Boettiger, M. Drochner +27
We give an overview of the QPACE project, which is pursuing the development of a massively parallel, scalable supercomputer for LQCD. The machine is a three-dimensional torus of id…