Topological tunnelling with dynamical overlap fermions

Cundy, N.; Krieg, S.; Lippert, T.; Schäfer, A.

doi:10.1016/j.cpc.2008.09.010

Journal Article

PreJuSER-722

Topological tunnelling with dynamical overlap fermions

Cundy, N. ; Krieg, S.FZJ* ; Lippert, T.FZJ* ; Schäfer, A.

2009
North Holland Publ. Co. Amsterdam

Computer physics communications 180, 201 - 208 (2009) [10.1016/j.cpc.2008.09.010]

This record in other databases:

Please use a persistent id in citations: http://hdl.handle.net/2128/25421 doi:10.1016/j.cpc.2008.09.010

Abstract: Tunnelling between different topological sectors with dynamical chiral fermions is difficult because of a poor mass scaling of the pseudo-fermion estimate of the determinant. For small fermion masses it is virtually impossible using standard methods. However, by projecting out the small Wilson eigenvectors from the overlap operator. and treating the correction determinant exactly, we can significantly increase the rate of topological sector tunnelling and reduce substantially the auto-correlation time. We present and compare a number of different approaches, and advocate a method which allows topological tunnelling even at low mass with little addition to the computational cost. (C) 2008 Elsevier B.V. All rights reserved.

Keyword(s): J ; Hybrid Monte Carlo (auto) ; Chiral fermions (auto) ; Lattice QCD (auto)

Classification:

Note: Calculations were performed on the JUBL and Cray XD-1 computers at The Julich Supercomputing Center (JSC), at the Forschentrum Julich, Germany. N.C. is grateful for the support of grant 930183 from the EU RP-6 "Hadron Physics" project, from the DFG "Gitter-Hadronen Phanomenologie" project, number 458/14-4 and EU grant MC-EIF-CT-2004-506078.

Contributing Institute(s):

Research Program(s):