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arXiv · 0705.2928

The Tunneling Hybrid Monte-Carlo algorithm

Maarten Golterman·Yigal Shamir
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Abstract

The hermitian Wilson kernel used in the construction of the domain-wall and overlap Dirac operators has exceptionally small eigenvalues that make it expensive to reach high-quality chiral symmetry for domain-wall fermions, or high precision in the case of the overlap operator. An efficient way of suppressing such eigenmodes consists of including a positive power of the determinant of the Wilson kernel in the Boltzmann weight, but doing this also suppresses tunneling between topological sectors. Here we propose a modification of the Hybrid Monte-Carlo algorithm which aims to restore tunneling between topological sectors by excluding the lowest eigenmodes of the Wilson kernel from the molecular-dynamics evolution, and correcting for this at the accept/reject step. We discuss the implications of this modification for the acceptance rate.

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Maarten Golterman, Yigal Shamir. 2007-10-09. The Tunneling Hybrid Monte-Carlo algorithm. https://doi.org/10.1103/physrevd.76.094512

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