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

Study of real quadratic fields by using continued fractions

Research Project

Project/Area Number 15K04779
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Algebra
Research InstitutionAichi University of Education

Principal Investigator

Kishi Yasuhiro  愛知教育大学, 教育学部, 准教授 (60380375)

Co-Investigator(Kenkyū-buntansha) 冨田 耕史  名城大学, 理工学部, 准教授 (50300207)
Research Collaborator KAWAMOTO Fuminori  
Project Period (FY) 2015-04-01 – 2019-03-31
Project Status Completed (Fiscal Year 2018)
Budget Amount *help
¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Keywords数論 / 連分数 / 二次体 / イデアル類群 / 類数 / 代数学 / 実二次体
Outline of Final Research Achievements

The present research has mainly dealt with the continued fraction expansions of certain quadratic irrationals. The main results have been to find some properties of that of the minimal elements with even period and to obtain some relations between them. Moreover, we gave a lower bound for the class numbers of certain real quadratic fields by using the class number formula and the Yokoi invariant. As a result, we got a family of real quadratic fields with non-trivial class number.

Academic Significance and Societal Importance of the Research Achievements

本研究の第1の学術的意義は, 部分商の最大値やその個数, 実二次体の類数, 分岐の様子など様々な性質を関連づけた点である. 連分数から導かれる情報は多種多様であるが, それらをそれぞれに意味づけし整理することは, 今後の研究にも不可欠である. 第2の意義は, ある条件を満たす代数体を明示的に与えた点である. 様々なケースにおいて扱いやすいものを具体的に与えることは, 学術的貢献に値すると考える.

Report

(5 results)
  • 2018 Annual Research Report   Final Research Report ( PDF )
  • 2017 Research-status Report
  • 2016 Research-status Report
  • 2015 Research-status Report
  • Research Products

    (28 results)

All 2019 2018 2017 2016 2015 Other

All Int'l Joint Research (4 results) Journal Article (8 results) (of which Int'l Joint Research: 2 results,  Peer Reviewed: 8 results,  Open Access: 6 results) Presentation (14 results) (of which Int'l Joint Research: 3 results,  Invited: 2 results) Remarks (2 results)

  • [Int'l Joint Research] ハリスチャンドラ研究所(インド)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] ハリスチャンドラ研究所(インド)

    • Related Report
      2017 Research-status Report
  • [Int'l Joint Research] 高等科学院(韓国)

    • Related Report
      2016 Research-status Report
  • [Int'l Joint Research] ハリスチャンドラ研究所(インド)

    • Related Report
      2016 Research-status Report
  • [Journal Article] REAL QUADRATIC FIELDS, CONTINUED FRACTIONS, AND A CONSTRUCTION OF PRIMARY SYMMETRIC PARTS OF ELE TYPE2019

    • Author(s)
      F. Kawamoto, Y Kishi, H. Suzuki and K. Tomita
    • Journal Title

      Kyushu Journal of Mathematics

      Volume: 73 Issue: 1 Pages: 165-187

    • DOI

      10.2206/kyushujm.73.165

    • NAID

      130007728836

    • ISSN
      1340-6116, 1883-2032
    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Divisibility of the class numbers of imaginary quadratic fields2018

    • Author(s)
      K. Chakraborty, A. Hoque, Y Kishi and P. P. Pandey
    • Journal Title

      J. Number Theory

      Volume: 185 Pages: 339-348

    • DOI

      10.1016/j.jnt.2017.09.007

    • NAID

      120006767458

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] An infinite family of pairs of imaginary quadratic fields with both class numbers divisible by five2017

    • Author(s)
      Miho Aoki, Yasuhiro Kishi
    • Journal Title

      Journal of Number Theory

      Volume: 176 Pages: 333-343

    • DOI

      10.1016/j.jnt.2016.12.007

    • NAID

      120006706219

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] A construction of real quadratic fields of minimal type and primary symmetric parts of ELE type2017

    • Author(s)
      F. Kawamoto, Y. Kishi, H. Suzuki and K. Tomita
    • Journal Title

      RIMS Kokyuroku Bessatsu

      Volume: B64

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Journal Article] Imaginary quadratic fields whose ideal class groups have 3-rank at least three2017

    • Author(s)
      Y. Kishi and T. Komatsu
    • Journal Title

      Journal of Number Theory

      Volume: 170 Pages: 46-54

    • DOI

      10.1016/j.jnt.2016.06.019

    • NAID

      120006395530

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] A remark on the Lavallee-Spearman-Williams-Yang family of quadratic fields2017

    • Author(s)
      K.-S. Kim and Y. Kishi
    • Journal Title

      Mathematical Journal of Okayama University

      Volume: 59 Pages: 113-116

    • NAID

      120005898811

    • Related Report
      2016 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Continued Fraction Expansions with Even Period and Primary Symmetric Parts with Extremely Large End2015

    • Author(s)
      F. Kawamoto, Y. Kishi and K. Tomita
    • Journal Title

      Commentarii mathematici Universitatis Sancti Pauli = Rikkyo Daigaku sugaku zasshi

      Volume: 64 Issue: 2 Pages: 131-155

    • DOI

      10.14992/00011773

    • NAID

      120005695554

    • URL

      http://id.nii.ac.jp/1062/00011773/

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] On systems of fundamental units of certain quartic fields2015

    • Author(s)
      M. Aoki and Y. Kishi
    • Journal Title

      Int. J. Number Theory

      Volume: 11 Issue: 07 Pages: 2019-2035

    • DOI

      10.1142/s1793042115500864

    • Related Report
      2015 Research-status Report
    • Peer Reviewed
  • [Presentation] 偶数周期の最小元の性質について2018

    • Author(s)
      岸康弘
    • Organizer
      日本数学会2018年度秋季総合分科会
    • Related Report
      2018 Annual Research Report
  • [Presentation] ある実2次体の系列における類数の下からの評価2018

    • Author(s)
      岸康弘
    • Organizer
      日本数学会2018年度秋季総合分科会
    • Related Report
      2018 Annual Research Report
  • [Presentation] Finite sequences of ELE type and a lower bound for the class number of certain real quadratic fields2018

    • Author(s)
      Y Kishi
    • Organizer
      International Conference on Class Groups of Number Fields and Related Topics-2018
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] イデアル類群の3ランクが3以上になる虚2次体の族について2017

    • Author(s)
      小松亨、岸康弘
    • Organizer
      日本数学会2017年度年会
    • Place of Presentation
      首都大学東京(東京都八王子市)
    • Year and Date
      2017-03-24
    • Related Report
      2016 Research-status Report
  • [Presentation] Q(\sqrt{x^2-t^n})型虚2次体の類数のn-divisibility2017

    • Author(s)
      岸康弘
    • Organizer
      学習院整数論研究集会
    • Related Report
      2017 Research-status Report
  • [Presentation] 類数がpで割れる代数体のペアの構成2017

    • Author(s)
      岸康弘
    • Organizer
      2017大分熊本整数論研究集会
    • Related Report
      2017 Research-status Report
  • [Presentation] On some properties concerned with the continued fraction expansions of \sqrt{d} with even period2017

    • Author(s)
      Y. Kishi
    • Organizer
      International Conference on Class Groups of Number Fields and Related Topics
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 連分数展開における各偶数周期の最小元が持つ性質2017

    • Author(s)
      岸康弘
    • Organizer
      東京理科大学談話会
    • Related Report
      2017 Research-status Report
  • [Presentation] 各偶数周期の最小元が持つ性質について2017

    • Author(s)
      岸康弘
    • Organizer
      北陸数論セミナー
    • Related Report
      2017 Research-status Report
  • [Presentation] 類数が5で割れる虚2次体のペアの無限族について2016

    • Author(s)
      岸康弘
    • Organizer
      平成27年度日本数学会中国・四国支部例会
    • Place of Presentation
      広島大学(広島県東広島市)
    • Year and Date
      2016-01-24
    • Related Report
      2015 Research-status Report
  • [Presentation] 3-rankが3以上のイデアル類群を持つ虚2次体の構成2015

    • Author(s)
      岸康弘
    • Organizer
      新潟代数セミナー
    • Place of Presentation
      新潟大学(新潟県新潟市)
    • Year and Date
      2015-12-21
    • Related Report
      2015 Research-status Report
  • [Presentation] 3-rankが3以上のイデアル類群を持つ虚2次体の族について2015

    • Author(s)
      岸康弘
    • Organizer
      首都大整数論セミナー
    • Place of Presentation
      首都大学東京(東京都八王子市)
    • Year and Date
      2015-10-20
    • Related Report
      2015 Research-status Report
  • [Presentation] イデアル類群の3-rankが3以上となる虚2次体の構成2015

    • Author(s)
      岸康弘
    • Organizer
      愛知数論セミナー
    • Place of Presentation
      名古屋工業大学(愛知県名古屋市)
    • Year and Date
      2015-10-10
    • Related Report
      2015 Research-status Report
  • [Presentation] Imaginary quadratic fields whose ideal class groups have 3-rank at least three2015

    • Author(s)
      Y. Kishi
    • Organizer
      29th Journees Arithmetiques
    • Place of Presentation
      University of Debrecen, デブレツェン(ハンガリー)
    • Year and Date
      2015-07-09
    • Related Report
      2015 Research-status Report
    • Int'l Joint Research
  • [Remarks]

    • URL

      http://auemath.aichi-edu.ac.jp/~ykishi/paperE.html

    • Related Report
      2015 Research-status Report
  • [Remarks]

    • URL

      http://auemath.aichi-edu.ac.jp/~ykishi/talkE.html

    • Related Report
      2015 Research-status Report

URL: 

Published: 2015-04-16   Modified: 2020-03-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi