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Research on extremal combinatorics by Ramsey methods

Research Project

Project/Area Number 18K03396
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 12030:Basic mathematics-related
Research InstitutionShiga University

Principal Investigator

Shinohara Masashi  滋賀大学, 教育学系, 准教授 (70432903)

Co-Investigator(Kenkyū-buntansha) 野崎 寛  愛知教育大学, 教育学部, 准教授 (80632778)
Project Period (FY) 2018-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2021: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywords距離集合 / 正十二面体 / 極値組み合わせ論 / 点の配置問題 / 極値組合せ論 / 距離構造 / 組合せ論 / ラムゼー理論 / ラムゼー問題 / 正単体 / 極値集合論 / 組合せデザイン / 離散幾何学 / 離散数学 / 点配置問題
Outline of Final Research Achievements

In this reserch, our goal was to classify good point configurations into "Ramsey-type problems" and "constructive problems". Particularly noteworthy is that we were able to solve (i) optimality of the dodecahedron and (ii) optimality of Lisonek's point arrangement in the 8-dimensional Euclidean space. Our proposed method was highly effective for both problems. For problem (i), this was the final major challenge regarding regular polyhedra in the context of distance sets. For problem (ii), we were able to prove it using a constructive problem involving "classification of point configurations containing a regular simplex". These results have led us to conclude that the achievements of this study exceeded our initial expectations.

Academic Significance and Societal Importance of the Research Achievements

正多面体がよい配置であることは広く知られたことであろう.正多面体は多面体の面の性質に着目して「よい」と分類されたものであるが,他の観点からよい点配置を考えることができないかというのは自然な問いである.本研究では距離集合の観点からよい点配置について考えることを目標としている.
本研究の成果として,正多面体は距離集合としてもよい配置であることを明らかにした.具体的には,正十二面体の配置が 20 個の頂点をもち,各 2 頂点間の距離として 5 種類の距離をもつもの(5-距離集合)としてただ一つのものであることを示した.また,距離集合に関する分類問題の解決や他の組合せ論との関連性について明らかにした.

Report

(6 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (42 results)

All 2023 2022 2021 2020 2019 2018 Other

All Int'l Joint Research (4 results) Journal Article (12 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 10 results,  Open Access: 10 results) Presentation (26 results) (of which Int'l Joint Research: 5 results,  Invited: 8 results)

  • [Int'l Joint Research] Pusan National University(韓国)

    • Related Report
      2019 Research-status Report
  • [Int'l Joint Research] Univ. of Science and Technology of China(中国)

    • Related Report
      2019 Research-status Report
  • [Int'l Joint Research] University of Delaware(米国)

    • Related Report
      2019 Research-status Report
  • [Int'l Joint Research] Pusan National University(韓国)

    • Related Report
      2018 Research-status Report
  • [Journal Article] Rationality of the inner products of spherical s-distance t-designs for t≧2s-2, s≧32022

    • Author(s)
      Boyvalenkov Peter、Nozaki Hiroshi、Safaei Navid
    • Journal Title

      Linear Algebra and its Applications

      Volume: 646 Pages: 107-118

    • DOI

      10.1016/j.laa.2022.03.028

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] On the spectrum and linear programming bound for hypergraphs2022

    • Author(s)
      Sebastian M. Cioaba, Jack H. Koolen, Masato Mimura, Hiroshi Nozaki, and Takayuki Okuda
    • Journal Title

      European Journal of Combinatorics

      Volume: 104 Pages: 103535-103535

    • DOI

      10.1016/j.ejc.2022.103535

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] A Proof of a Dodecahedron Conjecture for Distance Sets2021

    • Author(s)
      Nozaki Hiroshi、Shinohara Masashi
    • Journal Title

      Graphs and Combinatorics

      Volume: 37 Issue: 5 Pages: 1585-1603

    • DOI

      10.1007/s00373-021-02318-5

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] ユークリッド空間上の距離集合の分類問題について2021

    • Author(s)
      篠原雅史
    • Journal Title

      第37回代数的組合せ論シンポジウム報告集

      Volume: - Pages: 98-104

    • Related Report
      2021 Research-status Report
  • [Journal Article] Maximal 2-distance sets containing the regular simplex2020

    • Author(s)
      Hiroshi Nozaki, Masashi Shinohara
    • Journal Title

      Discrete Mathematics

      Volume: 343 Issue: 11 Pages: 112071-112071

    • DOI

      10.1016/j.disc.2020.112071

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Characterization of finite colored spaces with certain conditions2019

    • Author(s)
      Mitsugu Hirasaka, Masashi Shinohara
    • Journal Title

      Journal of the Korean Mathematical Society

      Volume: 56 Pages: 579-594

    • Related Report
      2019 Research-status Report 2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Complementary Ramsey numbers and Ramsey graphs2019

    • Author(s)
      Akihiro Munemasa, Masashi Shinohara
    • Journal Title

      Journal of Indonesian Mathematical Society

      Volume: 25 Pages: 146-153

    • DOI

      10.22342/jims.25.2.827.146-153

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Largest regular multigraphs with three distinct eigenvalues2019

    • Author(s)
      Hiroshi Nozaki
    • Journal Title

      Discrete Mathematics

      Volume: 342 Issue: 7 Pages: 2134-2138

    • DOI

      10.1016/j.disc.2019.04.016

    • NAID

      120006732118

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] A spectral version of the Moore problem for bipartite regular graphs2019

    • Author(s)
      Sebastian Cioaba, Jack, Koolen, Hiroshi Nozaki
    • Journal Title

      Algebraic Combinatorics

      Volume: 2 Issue: 6 Pages: 1219-1238

    • DOI

      10.5802/alco.71

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] A spectral version of the Moore problem for bipartite regular graphs2019

    • Author(s)
      Sebastian Cioaba, Jack Koolen, Hiroshi Nozaki
    • Journal Title

      Algebraic Combinatorics

      Volume: -

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] 篠原雅史、宗政昭弘2018

    • Author(s)
      Complementary Ramsey numbers and Ramsey graphs
    • Journal Title

      応用数学合同研究集会報告集

      Volume: -

    • Related Report
      2018 Research-status Report
  • [Journal Article] Complex Spherical Codes with Three Inner Products2018

    • Author(s)
      Nozaki Hiroshi、Suda Sho
    • Journal Title

      Discrete & Computational Geometry

      Volume: 60 Issue: 2 Pages: 294-317

    • DOI

      10.1007/s00454-018-0017-x

    • NAID

      120006729497

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] 高次元空間の点配置と距離集合2023

    • Author(s)
      篠原雅史
    • Organizer
      数理情報科学さくらセミナー2023
    • Related Report
      2022 Annual Research Report
  • [Presentation] Bounds for sets with few distances distinct modulo a prime ideal2022

    • Author(s)
      野崎寛
    • Organizer
      第38回代数的組合せ論シンポジウム
    • Related Report
      2022 Annual Research Report
    • Invited
  • [Presentation] A generalization of mod-p bounds for s-distance sets to a ring of integers2022

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      Workshop on Algebraic Combinatorics
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] R^8 上の最良な 2-距離集合の一意性について2022

    • Author(s)
      篠原雅史
    • Organizer
      日本数学会
    • Related Report
      2021 Research-status Report
  • [Presentation] ユークリッド空間上の距離集合の分類問題について2021

    • Author(s)
      篠原雅史
    • Organizer
      第37回代数的組合せ論シンポジウム
    • Related Report
      2021 Research-status Report
    • Invited
  • [Presentation] Few distance sets and the dodecahedron conjecture2021

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      Moscow Conference on Combinatorics and Applications
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] A proof of the dodecahedron conjecture of distance sets and diameter graphs2021

    • Author(s)
      Masashi Shinohara
    • Organizer
      Moscow Conference on Combinatorics and Applications
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 直径グラフの独立数と距離集合2021

    • Author(s)
      篠原雅史
    • Organizer
      第 33 回位相幾何学的グラフ理論研究集会
    • Related Report
      2021 Research-status Report
  • [Presentation] 正多面体と距離集合2021

    • Author(s)
      篠原雅史
    • Organizer
      研究会 直感幾何学2021
    • Related Report
      2020 Research-status Report
  • [Presentation] 3 次元ユークリッド空間における距離集合の分類問題と関係するグラフ構造2021

    • Author(s)
      篠原雅史
    • Organizer
      数理情報科学さくらセミナー2021
    • Related Report
      2020 Research-status Report
  • [Presentation] 距離集合における正十二面体予想について2020

    • Author(s)
      篠原雅史
    • Organizer
      離散数学とその応用研究集会2020
    • Related Report
      2020 Research-status Report
  • [Presentation] Linear programming methods to obtain bounds on the order of regular graphs2020

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      Joint Workshop on Algebraic Combinatorics and Cryptography
    • Related Report
      2019 Research-status Report
  • [Presentation] Maximal 2-distance sets containing a regular simplex2019

    • Author(s)
      篠原雅史
    • Organizer
      日本数学会
    • Related Report
      2019 Research-status Report
  • [Presentation] 距離集合の研究に関する最近の進展の紹介と展望2019

    • Author(s)
      篠原雅史
    • Organizer
      組合せ論サマースクール2019
    • Related Report
      2019 Research-status Report
  • [Presentation] 距離集合における正十二面体予想について2019

    • Author(s)
      篠原雅史
    • Organizer
      第9回数理情報科学さくらセミナー
    • Related Report
      2019 Research-status Report
  • [Presentation] Linear programming bounds for regular uniform hypergraphs2019

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      The 22nd Conference of the International Linear Algebra Society(招待講演)(国際学会)
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Maximal 2-distance sets containing the regular simplex2019

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      Tenth Discrete Geometry and Algebraic Combinatorics Conference
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Linear programming bounds for regular uniform hypergraphs2019

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      Sendai Workshop on Combinatorics
    • Related Report
      2019 Research-status Report
  • [Presentation] 正則一様ハイパーグラフにおける線形計画限界について2019

    • Author(s)
      野崎寛
    • Organizer
      日本数学会2019年度秋季総合分科会(応用数学)
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 点配置に関係する幾つかのラムゼー型問題について2019

    • Author(s)
      篠原雅史
    • Organizer
      数理情報科学さくらセミナー2019
    • Related Report
      2018 Research-status Report
  • [Presentation] Complementary Ramsey numbers and Ramsey graphs2019

    • Author(s)
      篠原雅史
    • Organizer
      幾何学と組合せ論2019
    • Related Report
      2018 Research-status Report
  • [Presentation] 少ない非合同三角形を持つ点配置についてⅢ2018

    • Author(s)
      篠原雅史
    • Organizer
      組合せ論サマースクール2018
    • Related Report
      2018 Research-status Report
  • [Presentation] Complementary Ramsey numbers and Ramsey graphs2018

    • Author(s)
      篠原雅史、宗政昭弘
    • Organizer
      2018 年度応用数学合同研究集会
    • Related Report
      2018 Research-status Report
  • [Presentation] Maximizing the order of regular bipartite graphs for given valency and second eigenvalue2018

    • Author(s)
      Hiroshi Nozaki
    • Organizer
      The Japanese Conference on Combinatorics and its Applications 2018
    • Related Report
      2018 Research-status Report
  • [Presentation] Maximal 2-distance sets containing the regular simplex2018

    • Author(s)
      野崎寛
    • Organizer
      Research on algebraic combinatorics, related groups and algebras
    • Related Report
      2018 Research-status Report
  • [Presentation] Linear programming bounds for regular uniform hypergraphs2018

    • Author(s)
      野崎寛
    • Organizer
      スペクトラルグラフ理論および周辺領域 第 7 回研究集会
    • Related Report
      2018 Research-status Report

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Published: 2018-04-23   Modified: 2024-01-30  

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