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arXiv · 1010.2592

Double-pass variants for multi-shift BiCGstab(ell)

Simon Heybrock
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Abstract

In analogy to Neuberger's double-pass algorithm for the Conjugate Gradient inversion with multi-shifts we introduce a double-pass variant for BiCGstab(ell). One possible application is the overlap operator of QCD at non-zero chemical potential, where the kernel of the sign function is non-Hermitian. The sign function can be replaced by a partial fraction expansion, requiring multi-shift inversions. We compare the performance of the new method with other available algorithms, namely partial fraction expansions with restarted FOM inversions and the Krylov-Ritz method using nested Krylov subspaces.

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Simon Heybrock. 2010-10-13. Double-pass variants for multi-shift BiCGstab(ell). https://arxiv.org/abs/1010.2592

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