2017/10/18 by Shoichiro Tsutsui, Takahiro Doi, Takahiro M. Doi
Mathematics · Physics and Astronomy · #Applied mathematics #Combinatorics #Function (biology) #Mathematical analysis #Mathematics #Monte Carlo method #Observable #Particle physics #Partition (number theory) #Partition function (quantum field theory) #Physics #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Sign (mathematics) #Simple (philosophy) #Statistical physics #Statistics #Theoretical and Computational Physics #hep-lat
paper · pdf · doi:10.1051/epjconf/201817511016
7 pages, 4 figures, talk presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spain
arxiv created 2017/10/18 · openalex publication_date 2018/01/01 · arxiv updated 2018/04/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The QCD at finite density is not well understood yet, where standard Monte Carlo simulation suffers from the sign problem. In order to overcome the sign problem, the method of Lefschetz thimble has been explored. Basically, the original sign problem can be less severe in a complexified theory due to the constancy of the imaginary part of an action on each thimble. However, global phase factors assigned on each thimble still remain. Their interference is not negligible in a situation where a large number of thimbles contribute to the partition function, and this could also lead to a sign problem. In this study, we propose a method to resolve this problem by modifying the structure of Lefschetz thimbles such that only a single thimble is relevant to the partition function. It can be shown that observables measured in the original and modified theories are connected by a simple identity. We exemplify that our method works well in a toy model.