3 research outputs found
Instanton Distribution in Quenched and Full QCD
In order to optimize cooling as a technique to study the instanton content of
the QCD vacuum, we have studied the effects of alternative algorithms, improved
actions and boundary conditions on the evolution of single instantons and
instanton anti-instanton pairs. Using these results, we have extracted and
compared the instanton content of quenched and full QCD.Comment: 3 pages, LaTeX file + 3 figures included, uses epsfig.sty and
espcrc2.sty. Talk presented at LATTICE96(topology
Chronological Inversion Method for the Dirac Matrix in Hybrid Monte Carlo
In Hybrid Monte Carlo simulations for full QCD, the gauge fields evolve
smoothly as a function of Molecular Dynamics time. Here we investigate improved
methods of estimating the trial or starting solutions for the Dirac matrix
inversion as superpositions of a chronological sequence of solutions in the
recent past. By taking as the trial solution the vector which minimizes the
residual in the linear space spanned by the past solutions, the number of
conjugate gradient iterations per unit MD time is decreased by at least a
factor of 2. Extensions of this basic approach to precondition the conjugate
gradient iterations are also discussed.Comment: 35 pages, 18 EPS figures A new "preconditioning" method, derived from
the Chronological Inversion, is described. Some new figures are appended.
Some reorganization of the material has taken plac