46,692 research outputs found
Accelerating Staggered Fermion Dynamics with the Rational Hybrid Monte Carlo (RHMC) Algorithm
Improved staggered fermion formulations are a popular choice for lattice QCD
calculations. Historically, the algorithm used for such calculations has been
the inexact R algorithm, which has systematic errors that only vanish as the
square of the integration step-size. We describe how the exact Rational Hybrid
Monte Carlo (RHMC) algorithm may be used in this context, and show that for
parameters corresponding to current state-of-the-art computations it leads to a
factor of approximately seven decrease in cost as well as having no step-size
errors.Comment: 4 pages, 2 figures, 1 tabl
Exact 2+1 flavour RHMC simulations
We consider the Rational Hybrid Monte Carlo algorithm for performing exact
2+1 flavour fermion simulations. The specific cases of ASQTAD and domain wall
fermions are considered. We find that in both cases the naive performance is
similar to conventional hybrid algorithms.Comment: 3 pages, no figure
Algorithm Shootout: R versus RHMC
We present initial results comparing the RHMC and R algorithms on large
lattices with small quark masses using chiral fermions. We also present results
concerning staggered fermions near the deconfinement/chiral phase transition.
We find that the RHMC algorithm not only eliminates the step-size error of the
R algorithm, but is also considerably more efficient. We discuss several
possibilities for further improvement to the RHMC algorithm.Comment: Proceedings from Lattice 2005 (Dublin
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