84 citations · 222 across the 12 of their papers we have counts for
8 papers · 1 filter
Optimizing Shift Selection in Multilevel Monte Carlo for Disconnected Diagrams in Lattice QCD
Travis Whyte, Andreas Stathopoulos, Eloy Romero +1
The calculation of disconnected diagram contributions to physical signals is a computationally expensive task in Lattice QCD. To extract the physical signal, the trace of the inver…
Probing for the Trace Estimation of a Permuted Matrix Inverse Corresponding to a Lattice Displacement
Heather Switzer, Andreas Stathopoulos, Eloy Romero +2
In this work, we study probing for the more general problem of computing the trace of a permutation of , say . The motivation comes from Lattice QCD where we need…
Algorithms for Disconnected Diagrams in Lattice QCD
Arjun Singh Gambhir, Andreas Stathopoulos, Kostas Orginos +3
Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propag…
Deflation as a Method of Variance Reduction for Estimating the Trace of a Matrix Inverse
Arjun Singh Gambhir, Andreas Stathopoulos, Kostas Orginos
Many fields require computing the trace of the inverse of a large, sparse matrix. The typical method used for such computations is the Hutchinson method which is a Monte Carlo (MC)…
Extending the eigCG algorithm to nonsymmetric Lanczos for linear systems with multiple right-hand sides
A. M. Abdel-Rehim, Andreas Stathopoulos, Kostas Orginos
The technique that was used to build the EigCG algorithm for sparse symmetric linear systems is extended to the nonsymmetric case using the BiCG algorithm. We show that, similarly…
Hierarchical probing for estimating the trace of the matrix inverse on toroidal lattices
Andreas Stathopoulos, Jesse Laeuchli, Kostas Orginos
The standard approach for computing the trace of the inverse of a very large, sparse matrix is to view the trace as the mean value of matrix quadratures, and use the Monte Carl…
Extending the eigCG algorithm to non-symmetric linear systems with multiple right-hand sides
Abdou Abdel-Rehim, Kostas Orginos, Andreas Stathopoulos
For Hermitian positive definite linear systems and eigenvalue problems, the eigCG algorithm is a memory efficient algorithm that solves the linear system and simultaneously compute…
Computing and deflating eigenvalues while solving multiple right hand side linear systems in Quantum Chromodynamics
Andreas Stathopoulos, Kostas Orginos
We present a new algorithm that computes eigenvalues and eigenvectors of a Hermitian positive definite matrix while solving a linear system of equations with Conjugate Gradient (CG…