Challenge to the sign problem via path optimization

• Project/Area Number: 19H01898
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Kyoto University
• Principal Investigator: 大西 明 京都大学, 基礎物理学研究所, 教授 (70250412)
• Co-Investigator(Kenkyū-buntansha): 柏 浩司 福岡工業大学, 情報工学部, 教授 (50612123)
• Project Period (FY): 2019 – 2022
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥14,690,000 (Direct Cost: ¥11,300,000、Indirect Cost: ¥3,390,000); Fiscal Year 2022: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2021: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000); Fiscal Year 2020: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000); Fiscal Year 2019: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
• Keywords: 符号問題 / 格子QCD / 経路最適化 / ニューラルネットワーク / QCD相図 / 機械学習 / 径路最適化

Outline of Research at the Start

原子核・重イオン衝突・コンパクト天体現象などでは高密度の核物質が現れるが、高密度核物質の相図や状態方程式はいまだに基礎理論(QCD)から理解されていない。これはクォークや核子などのフェルミオンを含む有限密度系では、符号問題と呼ばれる理論物理学の大問題が現れるためである。本研究では経路積分の変数を複素化し、機械学習で用いられているニューラルネットワークを用いて、符号問題が小さくなるよう積分径路を最適化する手法(径路最適化法)を発展させ、有限密度QCDの符号問題に挑戦する。まずは取り組みやすい低次元化した理論等を調べるとともに計算量の削減方法を探し、より現実的な系の研究へと進む予定である。

Outline of Annual Research Achievements

令和4年度は以下の三つの研究を遂行した。まず一つ目として、物理的な性質を考慮したネットワークの経路最適化法への導入を行った。具体的には先行研究において、格子QCD計算分野で知られているStout smearingを利用したニューラルネットワークが提案されているため、このネットワークを改良し積分変数を複素化するネットワークとして導入した。このネットワークを用いることで、ゲージ固定を行なわなくても学習が進むことを示した。関連して、ゲージ変換を利用して配位を増やすことで学習を安定化させる手法の検討も行なったが、この方法は物理的な性質を考慮したネットワークほどは有効ではない事が分かった。また、有限密度QCDのような大きな系かつ複雑な系を調べるためには、ヤコビアンの数値計算時間の削減が急務である。そこで二つ目の研究として、計算時間削減のためヤコビアンの近似をおこなった。計算時間削減の手法は様々提案されているが、本年度はヤコビアンを学習時に単位行列で近似する最もドラスティックな近似を行った。少なくともこの近似の元、複素結合をもつU(1)ゲージ理論やθ項入りのU(1)ゲージ理論の学習は若干の誤差増加を伴うものの問題なく行えることが分かった。三つ目の研究としては、非常に厳しい符号問題が生じる、Hubbard-Stranovich変換を用いてハイブリッドモンテカルロ計算可能にしたイジング模型を例にして、学習時の配位の混合、学習が進むにつれて学習率を減少させる手法、損失関数へのペナルティー項の導入の性能評価を進めた。これらの改良は学習を安定化させる事が分かりつつある。以上の結果は、有限密度QCDへの経路最適化法を適用するための不可欠な手法が整ったことを意味する。近い将来の経路最適化法の有限密度QCDへの適用の可能性が拓かれた。

Research Progress Status

令和4年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和4年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Duke University(米国)
• [Int'l Joint Research] Technical University of Munich(ドイツ)
• [Int'l Joint Research] Fudan University(中国)
• [Int'l Joint Research] Yonsei University/Kangwon National University(韓国)
• [Int'l Joint Research] Technical University of Munich/University of Munich/GSI(ドイツ)
• [Int'l Joint Research] Michigan State University/Texas A&M University/Lawrence Berkeley National Laboratory(米国)
• [Int'l Joint Research] Chinese Academy of Sciences, Beijing/Nankai University/Chinese Academy of Sciences, Shanghai(中国)
• [Int'l Joint Research] INFN-LNS, Catania(イタリア)
• [Int'l Joint Research] INFN-HH, Magurele-Bucharest(ルーマニア)
• [Int'l Joint Research]
• [Journal Article] Improving efficiency of the path optimization method for a gauge theory (2023)
  • Author(s): Namekawa Yusuke、Kashiwa Kouji、Matsuda Hidefumi、Ohnishi Akira、Takase Hayato
  • Journal Title: Physical Review D Volume: 107 Issue: 3 Pages: 3-034509
  • DOI: 10.1103/physrevd.107.034509
  • Peer Reviewed / Open Access
• [Journal Article] Some Aspects of Persistent Homology Analysis on Phase Transition : Examples in an Effective QCD Model with Heavy Quarks (2023)
  • Author(s): Hayato Antoku and Kouji Kashiwa
  • Journal Title: Universe Volume: 9 Issue: 2 Pages: 1-11
  • DOI: 10.3390/universe9020082
  • Peer Reviewed / Open Access
• [Journal Article] Directed flow of Lambda in high-energy heavy-ion collisions and Lambda potential in dense nuclear matter (2022)
  • Author(s): Yasushi Nara, Asanosuke Jinno, Koichi Murase, Akira Ohnishi
  • Journal Title: PHYSICAL REVIEW Volume: 106 Issue: 4
  • DOI: 10.1103/physrevc.106.044902
  • Peer Reviewed / Open Access
• [Journal Article] Persistent Homology Analysis for Dense QCD Effective Model with Heavy Quarks (2022)
  • Author(s): Kashiwa Kouji、Hirakida Takehiro、Kouno Hiroaki
  • Journal Title: Symmetry Volume: 14 Issue: 9 Pages: 1783-1783
  • DOI: 10.3390/sym14091783
  • Peer Reviewed / Open Access
• [Journal Article] Multiplicity, probabilities, and canonical sectors for cold QCD matter (2022)
  • Author(s): Kashiwa Kouji、Kouno Hiroaki
  • Journal Title: Physical Review D Volume: 105 Issue: 5
  • DOI: 10.1103/physrevd.105.054017
  • Peer Reviewed / Open Access
• [Journal Article] Gauge invariant input to neural network for path optimization method (2022)
  • Author(s): Yusuke Namekawa, Kouji Kashiwa, Akira Ohnishi, Hayato Takase
  • Journal Title: Phys. Rev. D Volume: 105 Issue: 3 Pages: 034502-034502
  • DOI: 10.1103/physrevd.105.034502
  • Peer Reviewed / Open Access
• [Journal Article] Femtoscopic study of coupled-channel N Xi and Lambda Lambda interactions (2022)
  • Author(s): Kamiya Y.、Sasaki K.、Fukui T.、Hyodo T.、Morita K.、Ogata K.、Ohnishi A.、Hatsuda T.
  • Journal Title: Physical Review C Volume: 105 Issue: 1 Pages: 014915-014915
  • DOI: 10.1103/physrevc.105.014915
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] JAM mean-field update: mean-field effects on collective flow in high-energy heavy-ion collisions at $\sqrt{s_{NN}}=$ 2竏?20 GeV energies (2022)
  • Author(s): Yasushi Nara, Akira Ohnishi
  • Journal Title: Phys. Rev. C Volume: 105 Issue: 1
  • DOI: 10.1103/physrevc.105.014911
  • Peer Reviewed / Open Access
• [Journal Article] Nonanalyticity, sign problem, and Polyakov line in a Z3-symmetric heavy quark model at low temperature: Phenomenological model analyses (2021)
  • Author(s): Kouno Hiroaki、Kashiwa Kouji、Hirakida Takehiro
  • Journal Title: Physical Review D Volume: 104 Issue: 1
  • DOI: 10.1103/physrevd.104.014012
  • Peer Reviewed / Open Access
• [Journal Article] Anatomy of the dense QCD matter from canonical sectors (2021)
  • Author(s): Kashiwa Kouji、Kouno Hiroaki
  • Journal Title: Physical Review D Volume: 103 Issue: 11
  • DOI: 10.1103/physrevd.103.114020
  • Peer Reviewed / Open Access
• [Journal Article] Replica evolution of classical fields in 4+1 dimensional spacetime toward real time dynamics of quantum fields (2021)
  • Author(s): Akira Ohnishi, Hidefumi Matsuda, Teiji Kunihiro, Toru T. Takahashi
  • Journal Title: Prog. Theor. Exp. Phys. Volume: 2021 Issue: 2
  • DOI: 10.1093/ptep/ptaa172
  • Peer Reviewed / Open Access
• [Journal Article] Information theoretical view of QCD effective model with heavy quarks (2021)
  • Author(s): Kashiwa Kouji、Kouno Hiroaki
  • Journal Title: Physical Review D Volume: 103 Issue: 1 Pages: 1-9
  • DOI: 10.1103/physrevd.103.014014
  • Peer Reviewed / Open Access
• [Journal Article] Shear viscosity of a classical Yang-Mills field (2020)
  • Author(s): Hidefumi Matsuda, Teiji Kunihiro, Berndt M{\"u}ller, Akira Ohnishi, Toru T. Takahashi
  • Journal Title: Phys. Rev. D Volume: 102 Issue: 11
  • DOI: 10.1103/physrevd.102.114503
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Universality in COVID-19 spread in view of the Gompertz function (2020)
  • Author(s): Akira Ohnishi, Yusuke Namekawa, Tokuro Fukui
  • Journal Title: Prog. Theory. Exp. Phys. Volume: 2020 Issue: 12
  • DOI: 10.1093/ptep/ptaa148
  • Peer Reviewed / Open Access
• [Journal Article] Signatures of the vortical quark-gluon plasma in hadron yields (2020)
  • Author(s): Taya Hidetoshi, Park Aaron, Cho Sungtae, Gubler Philipp, Hattori Koichi, Hong Juhee, Huang Xu-Guang, Lee Su Houng, Monnai Akihiko, Ohnishi Akira, Oka Makoto, Yang Di-Lun
  • Journal Title: Physical Review C Volume: 102 Issue: 2 Pages: 021901-021901
  • DOI: 10.1103/physrevc.102.021901
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Statistical double $\Lambda$ hypernuclear formation from $\Xi^-$ absorption at rest in light nuclei (2020)
  • Author(s): Akira Ohnishi, Chikako Ishizuka, Kohsuke Tsubakihara, Yuichi Hirata
  • Journal Title: Prog. Theor. Exp. Phys. Volume: 2020 Issue: 6
  • DOI: 10.1093/ptep/ptaa047
  • NAID: 120006996969
  • Peer Reviewed / Open Access
• [Journal Article] Shear viscosity of classical massless fields in scalar theory (2020)
  • Author(s): Hidefumi Matsuda, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
  • Journal Title: Prog. Theor. Exp. Phys. Volume: 2020 Issue: 5
  • DOI: 10.1093/ptep/ptaa058
  • Peer Reviewed / Open Access
• [Journal Article] K-p Correlation Function from High-Energy Nuclear Collisions and Chiral SU(3) Dynamics (2020)
  • Author(s): Kamiya Yuki、Hyodo Tetsuo、Morita Kenji、Ohnishi Akira、Weise Wolfram
  • Journal Title: Physical Review Letters Volume: 124 Issue: 13 Pages: 132501-132501
  • DOI: 10.1103/physrevlett.124.132501
  • NAID: 130008155890
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The path optimization for the sign problem of low dimensional QCD (2020)
  • Author(s): Mori Yuto、Kashiwa Kouji、Ohnishi Akira
  • Journal Title: Proceedings of Science Volume: 363 (LATTICE2019) Pages: 183-183
  • DOI: 10.22323/1.363.0183
  • Peer Reviewed / Open Access
• [Journal Article] Evading the model sign problem in the PNJL model with repulsive vector-type interaction via path optimization (2020)
  • Author(s): Akira Ohnishi, Yuto Mori, Kouji Kashiwa
  • Journal Title: Proceedings of Science Volume: 363(LATTICE2019) Pages: 213-213
  • DOI: 10.22323/1.363.0213
  • Peer Reviewed / Open Access
• [Journal Article] Dynamically Integrated Transport Model for High-energy Nuclear Collisions at 3<$\sqrt{s_{NN}}$<30 GeV (2020)
  • Author(s): Koichi Murase, Yukinao Akamatsu, Masayuki Asakawa, Tetsufumi Hirano, Masakiyo Kitazawa, Kenji Morita, Yasushi Nara, Chiho Nonaka, Akira Ohnishi
  • Journal Title: JPS Conf. Proc. Volume: 32
  • DOI: 10.7566/jpscp.32.010081
  • Peer Reviewed / Open Access
• [Journal Article] Neutron-Proton Dynamics and Pion Production in Heavy-ion Collisions by the AMD+JAM Approach (2020)
  • Author(s): Natsumi Ikeno, Akira Ono, Yasushi Nara, Akira Ohnishi
  • Journal Title: JPS Conference Proceedings Volume: 32 Pages: 010067-010067
  • DOI: 10.7566/jpscp.32.010067
  • Peer Reviewed / Open Access
• [Journal Article] Study of $\bar{K}N$ interaction from the hadron-hadron correlation in high-energy nuclear collisions (2020)
  • Author(s): Y. Kamiya, T. Hyodo, K. Morita and A. Ohnishi
  • Journal Title: Proc. of the 18th International Conference on Hadron Spectroscopy and Structure (HADRON2019) Volume: - Pages: 656-660
  • DOI: 10.1142/9789811219313_0112
  • Peer Reviewed / Open Access
• [Journal Article] Persistent homology analysis of deconfinement transition in effective Polyakov-line model (2020)
  • Author(s): Hirakida Takehiro、Kashiwa Kouji、Sugano Junpei、Takahashi Junichi、Kouno Hiroaki、Yahiro Masanobu
  • Journal Title: International Journal of Modern Physics A Volume: 35 Issue: 10 Pages: 2050049-2050049
  • DOI: 10.1142/s0217751x20500499
  • Peer Reviewed / Open Access
• [Journal Article] Extension to imaginary chemical potential in a holographic model (2020)
  • Author(s): Ghoroku Kazuo、Kashiwa Kouji、Nakano Yoshimasa、Tachibana Motoi、Toyoda Fumihiko
  • Journal Title: Physical Review D Volume: 102 Issue: 4
  • DOI: 10.1103/physrevd.102.046003
  • Peer Reviewed / Open Access
• [Journal Article] Path optimization for U(1) gauge theory with complexified parameters (2020)
  • Author(s): Kashiwa Kouji、Mori Yuto
  • Journal Title: Physical Review D Volume: 102 Issue: 5 Pages: 1-7
  • DOI: 10.1103/physrevd.102.054519
  • Peer Reviewed / Open Access
• [Journal Article] Probing ΩΩ and pΩ dibaryons with femtoscopic correlations in relativistic heavy-ion collisions (2020)
  • Author(s): Morita Kenji、Gongyo Shinya、Hatsuda Tetsuo、Hyodo Tetsuo、Kamiya Yuki、Ohnishi Akira
  • Journal Title: Physical Review C Volume: 101 Issue: 1 Pages: 015201-015201
  • DOI: 10.1103/physrevc.101.015201
  • Peer Reviewed / Open Access
• [Journal Article] Effects of Pauli blocking on pion production in central collisions of neutron-rich nuclei (2020)
  • Author(s): Natsumi Ikeno, Akira Ono, Yasushi Nara, Akira Ohnishi
  • Journal Title: Phys. Rev. C Volume: 101 Issue: 3 Pages: 34607-34607
  • DOI: 10.1103/physrevc.101.034607
  • Peer Reviewed / Open Access
• [Journal Article] Application of the path optimization method to the sign problem in an effective model of QCD with a repulsive vector-type interaction (2019)
  • Author(s): Kashiwa Kouji、Mori Yuto、Ohnishi Akira
  • Journal Title: Physical Review D Volume: 99 Issue: 11 Pages: 114005-114005
  • DOI: 10.1103/physrevd.99.114005
  • NAID: 120006778265
  • Peer Reviewed / Open Access
• [Journal Article] Path optimization in 0+1D QCD at finite density (2019)
  • Author(s): Yuto Mori, Kouji Kashiwa, Akira Ohnishi
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2019 Issue: 11
  • DOI: 10.1093/ptep/ptz111
  • Peer Reviewed / Open Access
• [Journal Article] Comparison of heavy-ion transport simulations: Collision integral with pions and Δ resonances in a box (2019)
  • Author(s): Akira Ono, Jun Xu, Maria Colonna, Pawel Danielewicz, Che Ming Ko, Manyee Betty Tsang, Yong-Jia Wang, Hermann Wolter, Ying-Xun Zhang, et al.
  • Journal Title: Phys. Rev. C Volume: 100 Issue: 4
  • DOI: 10.1103/physrevc.100.044617
  • NAID: 120006956356
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Phase transition encoded in neural network (2019)
  • Author(s): Kashiwa Kouji、Kikuchi Yuta、Tomiya Akio
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2019 Issue: 8
  • DOI: 10.1093/ptep/ptz082
  • Peer Reviewed / Open Access
• [Journal Article] Color superconductivity in a holographic model (2019)
  • Author(s): Ghoroku Kazuo、Kashiwa Kouji、Nakano Yoshimasa、Tachibana Motoi、Toyoda Fumihiko
  • Journal Title: Physical Review D Volume: 99 Issue: 10 Pages: 106011-106011
  • DOI: 10.1103/physrevd.99.106011
  • Peer Reviewed / Open Access
• [Journal Article] Roberge-Weiss periodicity, canonical sector, and modified Polyakov loop (2019)
  • Author(s): Kashiwa Kouji、Kouno Hiroaki
  • Journal Title: Physical Review D Volume: 100 Issue: 9 Pages: 094023-094023
  • DOI: 10.1103/physrevd.100.094023
  • Peer Reviewed / Open Access
• [Journal Article] Imaginary Chemical Potential, NJL-Type Model and Confinement?Deconfinement Transition (2019)
  • Author(s): Kashiwa Kouji
  • Journal Title: Symmetry Volume: 11 Issue: 4 Pages: 562-562
  • DOI: 10.3390/sym11040562
  • Peer Reviewed / Open Access
• [Journal Article] Quark matter symmetry energy effects on hadron-quark coexistence in neutron star matter (2019)
  • Author(s): Xuhao Wu, Akira Ohnishi, Hong Shen
  • Journal Title: AIP Conf. Proc. Volume: 2127 Pages: 020032-020032
  • DOI: 10.1063/1.5117822
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Path Optimization for the Sign Problem in Field Theories using Neural Network (2019)
  • Author(s): Akira Ohnishi, Yuto Mori, Kouji Kashiwa
  • Journal Title: JPS Conf. Proc. Volume: 26
  • DOI: 10.7566/jpscp.26.024011
  • Peer Reviewed / Open Access
• [Journal Article] Dynamically Integrated Transport Approach for High-Energy Nuclear Collisions at High Baryon Density (2019)
  • Author(s): Koichi Murase, Yukinao Akamatsu, Masayuki Asakawa, Tetsufumi Hirano, Masakiyo Kitazawa, Kenji Morita, Yasushi Nara, Chiho Nonaka, Akira Ohnishi
  • Journal Title: JPS Conference Proceedings Volume: 26 Pages: 024016-024016
  • DOI: 10.7566/jpscp.26.024016
  • Peer Reviewed / Open Access
• [Journal Article] Path optimization method with use of neural network for the sign problem in field theories (2019)
  • Author(s): Akira Ohnishi, Yuto Mori, Kouji Kashiwa
  • Journal Title: Proceedings of Science Volume: LATTICE2018 Pages: 023-023
  • DOI: 10.22323/1.334.0023
  • Peer Reviewed / Open Access
• [Presentation] Femtoscopy for flavored hadron-hadron interactions (2023)
  • Author(s): Akira Ohnishi
  • Organizer: The 59th International Winger Meeting on Nuclear Physics 2023
  • Int'l Joint Research
• [Presentation] 重イオン衝突でのフローによる高密度核物質中のΛポテンシャルの検証 (2022)
  • Author(s): Akira Ohnishi
  • Organizer: 日本物理学会2022年秋季大会 2022
• [Presentation] Exploration of Efficient Neural Network for Path Optimization Method (2022)
  • Author(s): Yusuke Namekawa
  • Organizer: 瀬戸内サマーインスティテュート 2022
• [Presentation] Exploration of Efficient Neural Network for Path Optimization Method (2022)
  • Author(s): Yusuke Namekawa
  • Organizer: 熱場の量子論とその応用 2022
• [Presentation] Exploration of Efficient Neural Network for Path Optimization Method (2022)
  • Author(s): Yusuke Namekawa
  • Organizer: The 39th International Symposium on Lattice Field Theory
  • Int'l Joint Research
• [Presentation] Directed flow of Λ from heavy-ion collisions and hyperon puzzle of neutron stars (2022)
  • Author(s): Akira Ohnishi
  • Organizer: HYP 2022 XVIII International Conference on Hyperbolic Problems 2022
  • Int'l Joint Research
• [Presentation] 重イオン衝突におけるハドロン相関に関する理論とその展望 (2021)
  • Author(s): Akira Ohnishi
  • Organizer: ELPH研究会C031 2021
• [Presentation] Gauge invariant input to neural network for path optimization method (2021)
  • Author(s): Yusuke Namekawa
  • Organizer: YITP workshop "QCD phase diagram and lattice QCD 2021"
  • Int'l Joint Research
• [Presentation] Gauge invariant input to neural network for path optimization method (2021)
  • Author(s): Yusuke Namekawa
  • Organizer: 熱場の量子論研究会2021
• [Presentation] Persistent homology analysis for QCD effective models (2021)
  • Author(s): Kouji Kashiwa
  • Organizer: The 38th International Symposium on Lattice Field Theory
  • Int'l Joint Research
• [Presentation] Exploring the Phase Structure of QCD Effective Models with Persistent homology (2021)
  • Author(s): Kouji Kashiwa
  • Organizer: SIAM Conference on Applied Algebraic Geometry
  • Int'l Joint Research
• [Presentation] カノニカル法に基づいたQCD相構造の研究 (2021)
  • Author(s): 柏 浩司
  • Organizer: 日本物理学会 2021年秋季大会
• [Presentation] カノニカル法を利用した有限密度QCD物質の研究 (2021)
  • Author(s): 柏 浩司
  • Organizer: 第127回日本物理学会九州支部例会
• [Presentation] 古典場のレプリカ発展における緩和過程 (12aV1-5) (2021)
  • Author(s): 大西明, 松田英史, 国広悌二, 高橋徹
  • Organizer: 日本物理学会第 76 回年次大会(2021年)
• [Presentation] Femtoscopic study of $N\Xi$ interaction and search for the $H$ dibaryon state around the $N\Xi$ threshold (2021)
  • Author(s): A. Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hatsuda, T. Hyodo, K. Morita, K. Ogata
  • Organizer: Yamada Conference LXXII: The 8th Asia-Pacific Conference on Few-Body Problems in Physics
  • Int'l Joint Research
• [Presentation] Dense QCD matter tackled by experiments, observations, and theory (2020)
  • Author(s): Akira Ohnishi
  • Organizer: KEK Theory Workshop 2020
  • Int'l Joint Research / Invited
• [Presentation] Hadron-hadron correlation functions and its relation to exotic hadron search (2020)
  • Author(s): Akira Ohnishi
  • Organizer: ALICE week 2020
  • Int'l Joint Research / Invited
• [Presentation] Replica evolution of classical field in 4+1 dimensional spacetime toward real time dynamics of quantum field (2020)
  • Author(s): Akira Ohnishi, H. Matsuda, T. Kunihiro, and T. T. Takahashi
  • Organizer: 10th Int. Conf. on Exact Renormalization Group 2020 (ERG2020)
  • Int'l Joint Research
• [Presentation] Replica evolution of classical field in 4+1 dimensional spacetime toward real time dynamics of quantum field (2020)
  • Author(s): 大西明, 松田英史, 国広悌二, 高橋徹
  • Organizer: 大阪大学原子核理論セミナー
  • Invited
• [Presentation] 4+1次元時空でのレプリカ発展による量子統計性をもつ古典場理論の提案 (17pSH-14) (2020)
  • Author(s): 大西明, 松田英史, 国広悌二, 高橋徹
  • Organizer: 日本物理学会2020年秋季大会
• [Presentation] Replica evolution of classical fieldin 4+1 dimensional spacetimetoward real time dynamics of quantum field (2020)
  • Author(s): Akira Ohnishi, Hidefumi Matsuda, Teiji Kunihiro1, Toru. T. Takahashi
  • Organizer: Asia-Pacific Symposium for Lattice Field Theory(APLAT 2020)
  • Int'l Joint Research
• [Presentation] Correlation functions of strange hadrons and their relevance to bound state search (2020)
  • Author(s): Akira Ohnishi
  • Organizer: 3rd Symposium on Clustering as a window on the hierarchical structure of quantum systems
  • Invited
• [Presentation] Exploring the QCD phase diagram with holographic models (2020)
  • Author(s): Kouji Kashiwa
  • Organizer: KEK Theory Workshop 2020
  • Int'l Joint Research / Invited
• [Presentation] Hadron-hadron correlation and interaction from high-energy nuclear collisions (2020)
  • Author(s): Akira Ohnishi
  • Organizer: The 15th Hadron Spectroscopy Cafe on Hadron interactions and Exotics in Heavy Ion collisions
  • Invited
• [Presentation] カノニカル法における Polyakov-loop paradox の研究 (2020)
  • Author(s): 柏浩司、河野宏明
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] Path optimization for the sign problem in low-dimensional QCD and QCD effective models at finite density (2019)
  • Author(s): Akira Ohnishi, Yuto Mori, Kouji Kashiwa
  • Organizer: YITP Molecule-type Workshop on Frontiers in Lattice QCD and related topics
  • Int'l Joint Research
• [Presentation] 静止 Ξ- 反応からのハイパー核破片生成(Hyperfragment formation from Ξ- absorption at rest on nuclei) (2019)
  • Author(s): 大西 明, 石塚知香子, 椿原康介, 平田雄一
  • Organizer: 「物質階層を横断する会」第４回 ～ハドロン・原子核・原子・分子合同ミーティング～
  • Invited
• [Presentation] AMD-QLによる12C+Ξ-反応研究 (2019)
  • Author(s): 石塚知香子, 椿原康介, 平田雄一, 大西 明
  • Organizer: 「物質階層を横断する会」第４回 ～ハドロン・原子核・原子・分子合同ミーティング～
  • Invited
• [Presentation] 重イオン衝突と中性子星 --- ハドロン相関とハドロン間相互作用を中心に --- (2019)
  • Author(s): 大西 明
  • Organizer: 高密度ハドロン・クォーク物質の諸相と中性子星の構造・進化
  • Invited
• [Presentation] 2 粒子運動量相関から探るハドロン間相互作用 (From hadron correlations to hadron interactions) (2019)
  • Author(s): 大西 明
  • Organizer: 第二回クラスター階層領域研究会 (Program for the 2nd Symposium on Clustering as a window on the hierarchical structure of quantum systems)
  • Invited
• [Presentation] Baryon-Baryon correlation from heavy-ion collisions and its implication to baryon-baryon interaction (2019)
  • Author(s): Akira Ohnishi
  • Organizer: FemTUM19
  • Int'l Joint Research / Invited
• [Presentation] Higher-order symmetry energy parameters and neutron star properties (2019)
  • Author(s): Akira Ohnishi, E. E. Kolomeitsev, James M. Lattimer, Ingo Tews, Xuhao Wu
  • Organizer: YITP long-term workshop on Multi-Messenger Astrophysics in the Gravitational Wave Era
  • Int'l Joint Research
• [Presentation] Evading the model sign problem in the PNJL model with repulsive vector-type interaction via path optimization (2019)
  • Author(s): Akira Ohnishi, Yuto Mori, Kouji Kashiwa
  • Organizer: The 37th International Symposium on Lattice Field Theory (Lattice 2019)
  • Int'l Joint Research
• [Presentation] The path optimization for the sign problem of low dimensional QCD (2019)
  • Author(s): Yuto Mori, Kouji Kashiwa, Akira Ohnishi
  • Organizer: The 37th International Symposium on Lattice Field Theory (Lattice 2019)
  • Int'l Joint Research
• [Presentation] Study of $\bar{K}N$ interaction from the hadron-hadron correlation in high-energy nuclear collisions (2019)
  • Author(s): Y. Kamiya, T. Hyodo, K. Morita and A. Ohnishi
  • Organizer: The 18th International Conference on Hadron Spectroscopy and Structure (HADRON2019)
  • Int'l Joint Research
• [Presentation] Toward solving the sign problem in dense QCD matter via the path optimization method (2019)
  • Author(s): Kouji Kashiwa, Yuto Mori, Akira Ohnishi
  • Organizer: Quarks and Compact Stars (QCS 2019)
  • Int'l Joint Research / Invited
• [Presentation] Uhlmann位相を利用した非閉じ込め相転移の研究 (2019)
  • Author(s): 柏浩司、河野宏明
  • Organizer: 第125回日本物理学会九州支部例会
• [Remarks] 大西明教授らの論文がPTEP誌のEditor's Choiceに選ばれました
  • URL: https://www.yukawa.kyoto-u.ac.jp/research/r316