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An upper bound for the number of elementary moves needed for unknotting an arc-presentation of the trivial knot

Research Project

Project/Area Number 25400100
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Geometry
Research InstitutionJapan Women's University

Principal Investigator

Hayashi Chuichiro  日本女子大学, 理学部, 教授 (20281321)

Project Period (FY) 2013-04-01 – 2016-03-31
Project Status Completed (Fiscal Year 2015)
Budget Amount *help
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords結び目 / 自明結び目 / アーク表示 / クロムウェル変形 / グリッド表示 / 位相幾何学 / 結び目理論 / レクタンギュラー表示 / マージ / エクスチェンジ / 上界 / arc表示 / exchange変形 / merge変形 / R変形 / rectangular diagram / 交差点数
Outline of Final Research Achievements

I performed studies below together with T. Ando, Y. Nishikawa and M. Hayashi. We showed that any knot diagram with n crossings can be deformed by an adequate ambient isotopy of the plane into a grid diagram with 2n+2 or less vertical lines, and that the system of Seifert circles of a knot diagram can be deformed by an ambient isotopy into a disjoint union of squares composed of 2 vertical lines and 2 horizontal lines, and simultaneously, arcs substituting the crossings into vertical lines. We showed that an exchange move or merge move between the top and the bottom horizontal edges of a grid diagram with n vertical edges can be realized by a sequence of no more than 3n^2-4n-4 Reidemeister moves. We calculated by computers that how many exchange moves are sufficient for deforming an arc-presentation of the trivial knot so that it admits a merge move when the number of arcs are small.

Report

(4 results)
  • 2015 Annual Research Report   Final Research Report ( PDF )
  • 2014 Research-status Report
  • 2013 Research-status Report
  • Research Products

    (6 results)

All 2015 2014 2013

All Journal Article (4 results) (of which Peer Reviewed: 4 results,  Acknowledgement Compliant: 2 results) Presentation (2 results)

  • [Journal Article] Realizing exterior Cromwell moves on rectangular diagrams by Reidemeister moves2014

    • Author(s)
      Tatsuo Ando, Chuichiro Hayashi and Yuki Nishikawa
    • Journal Title

      Journal of Knot Thoery and its Ramifications

      Volume: 23 Issue: 05 Pages: 1450023-1450023

    • DOI

      10.1142/s0218216514500230

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Rectangular Seifert circles and arcs system2014

    • Author(s)
      Tatuo Ando, Chuichiro Hayashi and Miwa Hayashi
    • Journal Title

      Journal of Knot Thoery and its Ramifications

      Volume: 23 Issue: 08 Pages: 1450041-1450041

    • DOI

      10.1142/s0218216514500412

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Unknotting rectangular diagrams of the trivial knot by exchangge moves2013

    • Author(s)
      Chuichiro Hayashi and Sayaka Yamada
    • Journal Title

      Journal of Knot Theory and its Ramifications

      Volume: 22 Issue: 11 Pages: 1-12

    • DOI

      10.1142/s0218216513500673

    • Related Report
      2013 Research-status Report
    • Peer Reviewed
  • [Journal Article] Canonical forms for operation tables of finite connected quandles2013

    • Author(s)
      Chuichiro Hayashi
    • Journal Title

      Communications in Algebra

      Volume: 41 Issue: 9 Pages: 3340-3349

    • DOI

      10.1080/00927872.2012.685532

    • Related Report
      2013 Research-status Report
    • Peer Reviewed
  • [Presentation] とあるカンドル彩色のさがし方2015

    • Author(s)
      林忠一郎
    • Organizer
      拡大KOOKセミナー
    • Place of Presentation
      神戸大学
    • Year and Date
      2015-08-21
    • Related Report
      2015 Annual Research Report
  • [Presentation] ライデマイスター変形に代えて2014

    • Author(s)
      林忠一郎
    • Organizer
      多様体のトポロジーの展望
    • Place of Presentation
      東京大学(東京都・目黒区)
    • Year and Date
      2014-11-30
    • Related Report
      2014 Research-status Report

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Published: 2014-07-25   Modified: 2019-07-29  

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