Selected inversion as key to a stable Langevin evolution across the QCD phase boundary
We present new results of full QCD at nonzero chemical potential. In PRD 92, 094516 (2015) the complex Langevin method was shown to break down when the inverse coupling decreases and enters the transition region from the deconfined to the confined phase. We found that the stochastic technique used t...
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2018-01-01
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Online Access: | https://doi.org/10.1051/epjconf/201817507003 |
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doaj-e126bdcced71426884f16b62d689ea2a2021-08-02T06:47:52ZengEDP SciencesEPJ Web of Conferences2100-014X2018-01-011750700310.1051/epjconf/201817507003epjconf_lattice2018_07003Selected inversion as key to a stable Langevin evolution across the QCD phase boundaryBloch JacquesSchenk OlafWe present new results of full QCD at nonzero chemical potential. In PRD 92, 094516 (2015) the complex Langevin method was shown to break down when the inverse coupling decreases and enters the transition region from the deconfined to the confined phase. We found that the stochastic technique used to estimate the drift term can be very unstable for indefinite matrices. This may be avoided by using the full inverse of the Dirac operator, which is, however, too costly for four-dimensional lattices. The major breakthrough in this work was achieved by realizing that the inverse elements necessary for the drift term can be computed efficiently using the selected inversion technique provided by the parallel sparse direct solver package PARDISO. In our new study we show that no breakdown of the complex Langevin method is encountered and that simulations can be performed across the phase boundary.https://doi.org/10.1051/epjconf/201817507003 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Bloch Jacques Schenk Olaf |
spellingShingle |
Bloch Jacques Schenk Olaf Selected inversion as key to a stable Langevin evolution across the QCD phase boundary EPJ Web of Conferences |
author_facet |
Bloch Jacques Schenk Olaf |
author_sort |
Bloch Jacques |
title |
Selected inversion as key to a stable Langevin evolution across the QCD phase boundary |
title_short |
Selected inversion as key to a stable Langevin evolution across the QCD phase boundary |
title_full |
Selected inversion as key to a stable Langevin evolution across the QCD phase boundary |
title_fullStr |
Selected inversion as key to a stable Langevin evolution across the QCD phase boundary |
title_full_unstemmed |
Selected inversion as key to a stable Langevin evolution across the QCD phase boundary |
title_sort |
selected inversion as key to a stable langevin evolution across the qcd phase boundary |
publisher |
EDP Sciences |
series |
EPJ Web of Conferences |
issn |
2100-014X |
publishDate |
2018-01-01 |
description |
We present new results of full QCD at nonzero chemical potential. In PRD 92, 094516 (2015) the complex Langevin method was shown to break down when the inverse coupling decreases and enters the transition region from the deconfined to the confined phase. We found that the stochastic technique used to estimate the drift term can be very unstable for indefinite matrices. This may be avoided by using the full inverse of the Dirac operator, which is, however, too costly for four-dimensional lattices. The major breakthrough in this work was achieved by realizing that the inverse elements necessary for the drift term can be computed efficiently using the selected inversion technique provided by the parallel sparse direct solver package PARDISO. In our new study we show that no breakdown of the complex Langevin method is encountered and that simulations can be performed across the phase boundary. |
url |
https://doi.org/10.1051/epjconf/201817507003 |
work_keys_str_mv |
AT blochjacques selectedinversionaskeytoastablelangevinevolutionacrosstheqcdphaseboundary AT schenkolaf selectedinversionaskeytoastablelangevinevolutionacrosstheqcdphaseboundary |
_version_ |
1721239935654035456 |