Improving the low-lying spectrum of the overlap kernel
Kamleh, W, Adams, D, Leinweber, D B, Williams, A G · CERN Document Server (European Organization for Nuclear Research) · 2001
The action of the overlap-Dirac operator on a vector is typically implemented in directly through a multi-shift conjugate gradient solver. The compute-time this takes to evaluate depends upon the condition number $\\kappa$ of the matrix that is used as the overlap kernel. We examine the low-lying spectra of various candidate kernels in an effort to optimise $\\kappa$, thereby speeding up the overlap evaluation.