DMCA
1 Non-Reversibility of Molecular Dynamics Trajectories (1996)
BibTeX
@MISC{Edwards961non-reversibility,
author = {R. G. Edwards and Ivan Horváth and A. D. Kennedy A},
title = {1 Non-Reversibility of Molecular Dynamics Trajectories},
year = {1996}
}
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Abstract
We study the non-reversibility of molecular dynamics trajectories arising from the amplification of rounding errors. We analyse the causes of such behaviour and give arguments, indicating that this does not pose a significant problem for Hybrid Monte Carlo computations. We present data for pure SU(3) gauge theory and for QCD with dynamical fermions on small lattices to illustrate and to support some of our ideas. The theory of the Hybrid Monte Carlo (HMC) algorithm [1] assumes the exact reversibility of its molecular dynamics (MD) trajectories. Leapfrog integration guarantees this unless the initial conjugate gradient (CG) vector is chosen in time asymmetric way or finite precision arithmetic is used. While the first condition is easily ensured in practice by using a fixed starting vector for every CG inversion, all numerical computations carried out using floating point arithmetic are subject to rounding errors.
Keyphrases
molecular dynamic trajectory initial conjugate gradient pure su present data molecular dynamic give argument hybrid monte carlo hybrid monte carlo computation small lattice first condition exact reversibility gauge theory leapfrog integration guarantee finite precision arithmetic numerical computation cg inversion significant problem time asymmetric way dynamical fermion
