Application of Domain Decomposition to the Evaluation of Fermion Determinant Ratios

Abstract

We analyze the fluctuations in the case of mass reweighting for N_f=2 Wilson fermions. We use a domain decomposition factorization of the fermion determinant. Ratios of determinants are estimated stochastically. We study the stochastic and the ensemble fluctuations as a function of the volume V and the mass shift Delta m. With our result it is possible to estimate the cost and the effectiveness of mass reweighting. In addition we introduce a stochastic estimation for the one flavor case without using the square root.

7 pages,6 figures. Proceedings of the 30th International Symposium on Lattice Field Theory, June 24-29 2012, Cairns, Australia. Figure 3 replaced