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Speeding up the HMC algorithm: Some new results

Martin Hasenbusch
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Abstract

We give some new performance results for the Hybrid Monte Carlo (HMC) simulation of dynamical clover-improved Wilson fermions using an improved pseudo-fermion action. The generalisation of even-odd preconditioning for the standard Wilson fermion matrix to the clover-improved case is not unique. In the literature the so called symmetric and asymmetric versions are discussed. Most of the previous simulations of dynamical clover-improved Wilson fermions were done with the asymmetric version. Only recently, the JLQCD collaboration has pointed out that the symmetric version leads to a better performance of the HMC algorithm. Here, we show that also in combination with an improved pseudo-fermion action, the symmetric version of even-odd preconditioning leads to a better performance. For our lightest quark mass, which corresponds to $m_{PS}/m_{V} \approx 0.44$, we see a gain in performance by a factor of about 1.3.

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Martin Hasenbusch. 2005-09-22. Speeding up the HMC algorithm: Some new results. https://arxiv.org/abs/hep-lat/0509080

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