Sign problem in $Z_3$-symmetric effective Polyakov-line model
Abstract
As an effective model corresponding to -symmetric QCD (-QCD), we construct a -symmetric effective Polyakov-line model (-EPLM) by using the logarithmic fermion effective action. Since -QCD tends to QCD in the zero temperature limit, -EPLM also agrees with the ordinary effective Polyakov-line model (EPLM) there; note that ordinary EPLM does not possess symmetry. Our main purpose is to discuss a sign problem appearing in -EPLM. The action of -EPLM is real, when the Polyakov line is not only real but also its images. This suggests that the sign problem becomes milder in -EPLM than in EPLM. In order to confirm this suggestion, we do lattice simulations for both EPLM and -EPLM by using the reweighting method with the phase quenched approximation. In the low-temperature region, the sign problem is milder in -EPLM than in EPLM. We also propose a new reweighting method. This makes the sign problem very weak in -EPLM.
Cite
@article{arxiv.1705.00665,
title = {Sign problem in $Z_3$-symmetric effective Polyakov-line model},
author = {Takehiro Hirakida and Junpei Sugano and Hiroaki Kouno and Junichi Takahashi and Masanobu Yahiro},
journal= {arXiv preprint arXiv:1705.00665},
year = {2017}
}
Comments
16 pages, 38 figures