FLIC Overlap Fermions

TL;DR

This paper discusses the use of FLIC overlap fermions, which improve the condition number of the overlap kernel, leading to significant computational speedups in lattice QCD simulations.

Contribution

The paper introduces the application of FLIC actions as overlap kernels, demonstrating their efficiency advantages over traditional Wilson kernels.

Findings

FLIC overlap fermions have better condition numbers.

Using FLIC kernels speeds up overlap action computations.

Progress has been made in implementing FLIC overlap fermions.

Abstract

The action of the overlap-Dirac operator on a vector is typically implemented indirectly through a multi-shift conjugate gradient solver. The compute-time required depends upon the condition number, $\kappa$, of the matrix that is used as the overlap kernel. While the Wilson action is typically used as the overlap kernel, the FLIC (Fat Link Irrelevant Clover) action has an improved condition number and provides up to a factor of two speedup in evaluating the overlap action. We summarize recent progress on the use of FLIC overlap fermions.