Diagonal Kenney-Laub Rational Approximation to the Overlap Dirac Operator
High Energy Physics - Lattice
2025-12-24 v1
Abstract
We propose a practical formulation of the overlap Dirac operator in lattice QCD that employs the diagonal Kenney-Laub rational iterates - expressed via their partial fraction decomposition - to approximate the matrix sign function. We investigate this approximation using the Brillouin operator as kernel, in addition to the standard Wilson Dirac operator. Numerical results show improved chiral symmetry preservation and computational efficiency compared to the Chebyshev polynomial approach.
Keywords
Cite
@article{arxiv.2512.20223,
title = {Diagonal Kenney-Laub Rational Approximation to the Overlap Dirac Operator},
author = {Stephan Durr and Stylianos Gregoriou and Giannis Koutsou},
journal= {arXiv preprint arXiv:2512.20223},
year = {2025}
}
Comments
8 pages, 15 figures, Proceedings of the 42nd International Symposium on Lattice Field Theory (LATTICE2025), 2-8 November 2025, Mumbai, India