Numerical Challenges in Lattice QCD 2022

Session

Numerical Solvers

15 Aug 2022, 10:40

Landhaus Nordhelle

Conveners

Numerical Solvers

• Andreas Frommer

Numerical Solvers

• Mike Peardon

32. Disconnected Diagrams and High-Degree GMRES Polynomials

Walter Wilcox

15/08/2022, 10:40

We build upon our lattice QCD POLY and HFPOLY methods by using high-degree polynomials in the context of noisy disconnected diagram evaluations. Using a new, stable form of the GMRES polynomial, we obtained a subtracted error reduction in the Wilson-Dirac scalar operator on the order of a tenth the error of the non-subtracted measurement. The associated trace of subtracted high-degree...

34. Analysis of block GMRES using a $^\ast$-algebra-based approach

Kirk Soodhalter (Trinity College Dublin)

15/08/2022, 11:20

We discuss the challenges of extending convergence results of classical Krylov subspace methods to their block counterparts and propose a new approach to this analysis. Block KSMs such as block GMRES are generalizations of classical KSMs, and are meant to iteratively solve linear systems with multiple right-hand sides (a.k.a. a block right-hand side) all-at-once rather than individually....

48. Computational strategies for nucleon matrix elements

Sara Collins

17/08/2022, 09:00

Nucleon matrix elements are a major lattice QCD input to the search of new physics. Their determination can be challenging, in particular at near physical quark masses. On the one hand large Euclidean time separations are necessary to determine ground state matrix elements. On...

49. Meson distillation profiles and their applications

Mr Juan Andres Urrea Nino (Bergische Universität Wuppertal)

17/08/2022, 09:40

An improvement to the widely used distillation technique is presented in the context of meson spectroscopy. Introducing meson profiles in distillation space and optimizing them for the different operators of interest significantly increases the overlap between the created states and the energy eigenstates at no considerable extra cost. These profiles give more versatility to the smearing...

37. New ideas and developments for solvers for distillation?

Juan Andres Urrea-Nino