1 citations · 2 across the 15 of their papers we have counts for
15 papers
An Integral-Based Framework for Preconditioning
Gustavo Ramirez-Hidalgo
The computation of the action of a matrix function on a vector, , is a major computational bottleneck for large, sparse matrices, particularly when unfavorable spectral dist…
Variance reduction with probing and Multilevel Monte Carlo in Lattice QCD
Andreas Frommer, Jose Jimenez-Merchan, Bruno Lang +2
Trace estimation is central in many lattice QCD computations, but the accuracy of the standard, stochastic Hutchinson method improves only with the square root of the sample size,…
Exploiting Task-Based Parallelism for the Red-Black Gauss-Seidel Method on 2D Grids
Shiting Long, Gustavo Ramirez-Hidalgo, Andreas Frommer +1
Gauss-Seidel is a well-established iterative method for the solution of linear systems, and multicoloring has been widely used to increase parallelism in iterative solution techniq…
Data-Driven Spectral Prediction for Accelerating Large-Scale Electronic Structure Calculations
Abhiram Badrinarayanan, Davor Davidovic, Edoardo Di Napoli +4
Simulating large molecular systems comprising thousands of atoms requires highly scalable methodologies. While modern Density Functional Theory (DFT) codes exhibit linear scaling,…
Probing and graph coloring techniques for trace estimation in Lattice QCD
Mario Papace, Andreas Frommer, Jose Jimenez-Merchan +3
The computation of , where is the Wilson-Dirac matrix of Lattice QCD, is a fundamental and computationally demanding task with applications to disconnected…
Revisiting recursive methods for Dyson and Keldysh in NEGF: Part I
Edoardo Di Napoli, Alessandro Pecchia, Gustavo Ramirez-Hidalgo
The simulation of quantum transport in nanodevices requires the solution of the Dyson and Keldysh equations, a task dominated by the inversion of massive, block-tridiagonal matrice…
Performance-Portable Optimization and Analysis of Multiple Right-Hand Sides in a Lattice QCD Solver
Shiting Long, Gustavo Ramirez-Hidalgo, Stepan Nassyr +3
Managing the high computational cost of iterative solvers for sparse linear systems is a known challenge in scientific computing. Moreover, scientific applications often face memor…
Using orthogonal projectors in multigrid multilevel Monte Carlo for trace estimation in lattice QCD
Andreas Frommer, Jose Jimenez-Merchan, Francesco Knechtli +2
We introduce a multigrid multilevel Monte Carlo method for stochastic trace estimation in lattice QCD based on orthogonal projections. This formulation extends the previously propo…
Extending DD-AMG on heterogeneous machines
Gustavo Ramirez-Hidalgo, Lianhua He, Ke-Long Zhang
Multigrid solvers are the standard in modern scientific computing simulations. Domain Decomposition Aggregation-Based Algebraic Multigrid, also known as the DD-AMG solver, is a…
Polynomial Preconditioning for the Action of the Matrix Square Root and Inverse Square Root
Andreas Frommer, Gustavo Ramirez-Hidalgo, Marcel Schweitzer +1
While preconditioning is a long-standing concept to accelerate iterative methods for linear systems, generalizations to matrix functions are still in their infancy. We go a further…
Deflated Multigrid Multilevel Monte Carlo
Andreas Frommer, Gustavo Ramirez-Hidalgo
In lattice QCD, the trace of the inverse of the discretized Dirac operator appears in the disconnected fermion loop contribution to an observable. As simulation methods get more an…
Krylov Subspace Recycling For Matrix Functions
Liam Burke, Andreas Frommer, Gustavo Ramirez-Hidalgo +1
We derive an augmented Krylov subspace method with subspace recycling for computing a sequence of matrix function applications on a set of vectors. The matrix is either fixed or ch…
Coarsest-level improvements in multigrid for lattice QCD on large-scale computers
Jesus Espinoza-Valverde, Andreas Frommer, Gustavo Ramirez-Hidalgo +1
Numerical simulations of quantum chromodynamics (QCD) on a lattice require the frequent solution of linear systems of equations with large, sparse and typically ill-conditioned mat…
A Multilevel Approach to Variance Reduction in the Stochastic Estimation of the Trace of a Matrix
Andreas Frommer, Mostafa Nasr Khalil, Gustavo Ramirez-Hidalgo
The trace of a matrix function f(A), most notably of the matrix inverse, can be estimated stochastically using samples< x,f(A)x> if the components of the random vectors x obey an a…
Detection of the adsorption of water monolayers through the ion oscillation frequency in the magnesium oxide lattice by means of Low Energy Electron Diffraction
M. Guevara-Bertsch, G. Ramírez-Hidalgo, A. Chavarría-Sibaja +3
We investigate the variation of the oscillation frequency of the Mg and O ions in the magnesium oxide lattice due to the interactions of the surface with water monola…