ar X iv : h ep - l at / 0 11 01 98 v 1 2 5 O ct 2 00 1 A comparative study of numerical methods for the overlap Dirac operator — a status report

نویسنده

  • H. van der Vorst
چکیده

Improvements of various methods to compute the sign function of the hermitian Wilson-Dirac matrix within the overlap operator are presented. An optimal partial fraction expansion (PFE) based on a theorem of Zolotarev is given. Benchmarks show that this PFE together with removal of converged systems within a multi-shift CG appears to approximate the sign function times a vector most efficiently. A posteriori error bounds are given.

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تاریخ انتشار 2001