• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Combinatorial structure on algebraic varieties in positive characteristics

Research Project

Project/Area Number 16K13749
Research Category

Grant-in-Aid for Challenging Exploratory Research

Allocation TypeMulti-year Fund
Research Field Algebra
Research InstitutionHiroshima University

Principal Investigator

Shimada Ichiro  広島大学, 理学研究科, 教授 (10235616)

Co-Investigator(Kenkyū-buntansha) 木村 俊一  広島大学, 理学研究科, 教授 (10284150)
奥田 隆幸  広島大学, 理学研究科, 講師 (40725131)
Project Period (FY) 2016-04-01 – 2019-03-31
Project Status Completed (Fiscal Year 2018)
Budget Amount *help
¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Keywords格子 / 符号 / 計算機アルゴリズム / K3曲面 / コンフィギュレーション / Leech 格子 / Conway 群 / extremal 格子 / 代数幾何学 / 組合せ論的構造 / フェルマー多様体
Outline of Final Research Achievements

We investigated various algebraic varieties from combinatorial point of view, and observed many interesting facts. During the investigation, we improved several algorithms for combinatorial calculations, and implemented them in our computers. Thanks to these algorithms, we have succeeded in probing geometric properties of some K3 and Enriques surfaces, and in particular, determined their automorphism groups.
We also made huge data about the Leech lattice. We hope this data will be helpful in future investigation of algebraic varieties from combinatorial point of view.

Academic Significance and Societal Importance of the Research Achievements

格子や符号といった組み合わせ論的な数学的対象は,安全で高速なデジタル通信を支える上で重要な役割を果たしており,良い格子,良い符号,良い組み合わせ論的対象を見つけることは数学の重要な課題の一つである.特に,対称性の高い特別な代数多様体の幾何学からは興味深い組み合わせ論的構造が得られることが多い.本研究においては,様々な代数多様体に現れる興味深い組み合わせ論的構造を調べた.

Report

(4 results)
  • 2018 Annual Research Report   Final Research Report ( PDF )
  • 2017 Research-status Report
  • 2016 Research-status Report
  • Research Products

    (28 results)

All 2019 2018 2017 2016 Other

All Journal Article (14 results) (of which Int'l Joint Research: 9 results,  Peer Reviewed: 14 results,  Open Access: 9 results,  Acknowledgement Compliant: 2 results) Presentation (7 results) (of which Int'l Joint Research: 6 results,  Invited: 7 results) Remarks (6 results) Funded Workshop (1 results)

  • [Journal Article] On an Enriques surface associated with a quartic Hessian surface2019

    • Author(s)
      Ichiro Shimada
    • Journal Title

      Canad. J. Math.

      Volume: 71 Issue: 1 Pages: 213-246

    • DOI

      10.4153/cjm-2018-022-7

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Connected components of the moduli of elliptic K3 surfaces.2018

    • Author(s)
      I. Shimada
    • Journal Title

      Michigan Math. J.

      Volume: 67 Issue: 3 Pages: 511-559

    • DOI

      10.1307/mmj/1528941621

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] On Edge's correspondence associated with dot 2222018

    • Author(s)
      Ichiro Shimada
    • Journal Title

      Eur. J. Math.

      Volume: 4 Issue: 1 Pages: 399-412

    • DOI

      10.1007/s40879-017-0183-z

    • Related Report
      2018 Annual Research Report 2017 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] An even extremal lattice of rank 642018

    • Author(s)
      I. Shimada
    • Journal Title

      J. Number Theory

      Volume: 185 Pages: 1-15

    • DOI

      10.1016/j.jnt.2017.10.028

    • Related Report
      2018 Annual Research Report 2017 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Numerical boundedness on rational equivalences of zero cycles on algebraic varieties with trivial CH_02018

    • Author(s)
      Kimura, Shun-Ichi and Sheng, Mao and Zhang, Mingwei
    • Journal Title

      Asian J. Math.

      Volume: 22 Issue: 3 Pages: 569-576

    • DOI

      10.4310/ajm.2018.v22.n3.a9

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Geodesics of Riemannian symmetric spaces included in reflective submanifolds2018

    • Author(s)
      Takayuki Okuda
    • Journal Title

      Contemporary perspectives in differential geometry and its related fields

      Volume: World Sci. Publ Pages: 21-32

    • DOI

      10.1142/9789813220911_0002

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Holes of the Leech lattice and the projective models of K3 surfaces2017

    • Author(s)
      Ichiro Shimada
    • Journal Title

      Math. Proc. Cambridge Philos. Soc.

      Volume: 163 Issue: 1 Pages: 125-143

    • DOI

      10.1017/s030500411600075x

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Holes of the Leech lattice and the projective models of K3 surfaces2017

    • Author(s)
      I. Shimada
    • Journal Title

      Math. Proc. Cambridge Philos. Soc.

      Volume: 印刷中

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] On a smooth quartic surface containing 56 lines which is isomorphic as a K3 surface to the Fermat quartic2016

    • Author(s)
      Shimada, Ichiro; Shioda, Tetsuji
    • Journal Title

      manuscripta mathematica

      Volume: - Issue: 1-2 Pages: 279-297

    • DOI

      10.1007/s00229-016-0886-3

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Some remarks on cubature formulas with linear operators2016

    • Author(s)
      Masatake Hirao, Takayuki Okuda, Masanori Sawa
    • Journal Title

      Journal of the Mathematical Society of Japan

      Volume: 68 Issue: 2 Pages: 711-735

    • DOI

      10.2969/jmsj/06820711

    • NAID

      130006887144

    • ISSN
      0025-5645, 1881-1167, 1881-2333
    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] A new relative bound for equiangular lines and nonexistence of tight spherical designs of harmonic index 42016

    • Author(s)
      Takayuki Okuda, Wei-Hsuan Yu
    • Journal Title

      European J. Combin.

      Volume: 53 Pages: 96-103

    • DOI

      10.1016/j.ejc.2015.11.003

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Homogeneous space with non virtually abelian discontinuous groups but without any proper SL(2,R)-action2016

    • Author(s)
      Takayuki Okuda
    • Journal Title

      Internat. J. Math.

      Volume: 27 Issue: 03 Pages: 1650018-1650018

    • DOI

      10.1142/s0129167x1650018x

    • Related Report
      2016 Research-status Report
    • Peer Reviewed
  • [Journal Article] Proper SL(2;R)-actions on homogeneous spaces2016

    • Author(s)
      Maciej Bochenski, Piotr Jastrzebski, Takayuki Okuda, Aleksy Tralle
    • Journal Title

      Internat. J. Math.

      Volume: 27 Issue: 13 Pages: 1650106-1650106

    • DOI

      10.1142/s0129167x16501068

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] On the topology of projective subspaces in complex Fermat varieties2016

    • Author(s)
      Degtyarev, Alex; Shimada, Ichiro
    • Journal Title

      Journal of the Mathematical Society of Japan

      Volume: 68 Issue: 3 Pages: 975-996

    • DOI

      10.2969/jmsj/06830975

    • NAID

      130005166133

    • ISSN
      0025-5645, 1881-1167, 1881-2333
    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Presentation] Enriques involutions on singular K3 surfaces of small discriminants (joint work with Davide Cesare Veniani)2019

    • Author(s)
      Ichiro Shimada
    • Organizer
      Arithmetic and Algebraic Geometry 2019
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] The elliptic modular surface of level 4 and its reduction modulo 32018

    • Author(s)
      Ichiro Shimada
    • Organizer
      Algebraic Geometry in Positive Characteristic and Related Topics
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] The elliptic modular surface of level 4 and its reduction modulo 32018

    • Author(s)
      Ichiro Shimada
    • Organizer
      Working Workshop on Calabi-Yau Varieties and Related Topics
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] An even extremal lattice of rank 642017

    • Author(s)
      Ichiro Shimada
    • Organizer
      組合せ論セミナー(東北大学情報科学研究科)
    • Related Report
      2017 Research-status Report
    • Invited
  • [Presentation] An Enriques involution of the Fermat quartic surface in characteristic 32017

    • Author(s)
      Ichiro Shimada
    • Organizer
      K3 surfaces and Realted Topics
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Connected components of the moduli of elliptic K3 surfaces2016

    • Author(s)
      Ichiro Shimada
    • Organizer
      The 4th Franco-Japanese-Vietnamese Singularities
    • Place of Presentation
      University Savoie Mont Blanc, France
    • Year and Date
      2016-11-09
    • Related Report
      2016 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] A smooth quartic surface containing 56 lines2016

    • Author(s)
      Ichiro Shimada
    • Organizer
      Algebra, geometry and topology of singularities
    • Place of Presentation
      Galatasaray University, Turkey
    • Year and Date
      2016-05-13
    • Related Report
      2016 Research-status Report
    • Int'l Joint Research / Invited
  • [Remarks] Computational data of K3 surfaces

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/K3andEnriques.html

    • Related Report
      2018 Annual Research Report
  • [Remarks] K3 曲面とエンリケス曲面

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/K3.html

    • Related Report
      2017 Research-status Report
  • [Remarks] Higman-Sims グラフと Hoffman-Singleton グラフ

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/HSgraphs.html

    • Related Report
      2017 Research-status Report
  • [Remarks] 格子

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/lattice.html

    • Related Report
      2017 Research-status Report
  • [Remarks] Ichiro Shimada

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/inde.html

    • Related Report
      2016 Research-status Report
  • [Remarks] Lattices

    • URL

      http://www.math.sci.hiroshima-u.ac.jp/~shimada/lattice.html

    • Related Report
      2016 Research-status Report
  • [Funded Workshop] Branched Coverings, Degenerations, and Related Topics 20182018

    • Related Report
      2017 Research-status Report

URL: 

Published: 2016-04-21   Modified: 2020-03-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi