2016/09/30 by Andrea Bussone, Michele Della Morte, Martin Hansen +1 · 1 citation
Physics and Astronomy · #hep-lat
paper · pdf · doi:10.1016/j.cpc.2017.05.011
Version accepted for publication in Computer Physics Communications. Discussion extended in a few points. Results unchanged. 15 pages, 9 figures
arxiv created 2017/05/16 · arxiv updated 2017/09/13
We consider the possibility of using reweighting techniques in order to correct for the breaking of unitarity when twisted boundary conditions are imposed on valence fermions in simulations of lattice gauge theories. We start by studying the properties of reweighting factors and their variances at tree-level. That leads us to the introduction of a factorization for the fermionic reweighting determinant. In the numerical, stochastic, implementation of the method, we find that the effect of reweighting is negligible in the case of large volumes but it is sizeable when the volumes are small and the twisting angles are large. More importantly, we find that for un-improved Wilson fermions, and in small volumes, the dependence of the critical quark mass on the twisting angle is quite pronounced and results in large violations of the continuum dispersion relation.