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Hypergeometric functions and Painleve equations

Research Project

Project/Area Number 16K05165
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Basic analysis
Research InstitutionHokkaido University

Principal Investigator

Iwasaki Katsunori  北海道大学, 理学研究院, 教授 (00176538)

Research Collaborator Ebisu Akihito  
Project Period (FY) 2016-04-01 – 2019-03-31
Project Status Completed (Fiscal Year 2018)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Keywords超幾何関数 / 隣接関係式 / 超幾何連分数 / 漸近解析 / 離散鞍点法 / 誤差評価 / ガンマ乗積表示 / パンルヴェ方程式 / 漸近展開 / 連分数展開 / 離散ラプラス法 / 周期解 / 特殊値 / 連分数
Outline of Final Research Achievements

For generalized hypergeometric functions 3F2(1) we developed a general theory of contiguous relations. We established the linear independence of contiguous functions, existence and uniquness of contiguous relations, and algorithms for calculating their coefficients, as well as their group symmetry. As an application we constructed an infinite number of 3F2(1) continued fractions and determined exactly the leading asymptotics of their truncation errors. To do so we developed a discrete analogue of saddle point method for obtaining the asymptotic behavior of hypergeometric series containing a large parameter. As for Painleve equations we summarized the results obtained so far and set up the direction in which the next study should take. We also obtained some conditions for hypergeometric functions to admit gamma product formulas.

Academic Significance and Societal Importance of the Research Achievements

超幾何関数やパンルヴェ方程式で定義される関数は、数学や数理物理学のさまざまな局面に現れる重要な特殊関数である。そこで、これらの関数に特徴的な性質を調べることや、関連する関数の計算手段を確立することは、数学や数理物理学にとって大変重要である。また、これらの目的を達成するために、漸化式・差分方程式や漸近解析などの分野に、隣接関係式の同時性や離散鞍点法などの概念や手法を導入することは、解析学に新し知見をもたらすことになり、有益である。

Report

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

    (14 results)

All 2019 2018 2017 2016

All Journal Article (3 results) (of which Peer Reviewed: 3 results) Presentation (11 results) (of which Int'l Joint Research: 1 results,  Invited: 4 results)

  • [Journal Article] Contiguous relations, Laplace's methods, and continued fractions for 3F2(1)2019

    • Author(s)
      Akihito Ebisu and Katsunori Iwasaki
    • Journal Title

      Ramanujan Journal

      Volume: - Issue: 1 Pages: 159-213

    • DOI

      10.1007/s11139-018-0039-2

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Three-term relations for 3F2(1)2018

    • Author(s)
      Akihito Ebisu and Katsunori Iwasaki
    • Journal Title

      J. Math. Anal. Appl.

      Volume: 463 Issue: 2 Pages: 593-610

    • DOI

      10.1016/j.jmaa.2018.03.034

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Journal Article] Hypergeometric series with gamma product formula2017

    • Author(s)
      Katsunori Iwasaki
    • Journal Title

      Indagationes Mathematicae

      Volume: 28 Issue: 2 Pages: 463-493

    • DOI

      10.1016/j.indag.2016.12.001

    • Related Report
      2016 Research-status Report
    • Peer Reviewed
  • [Presentation] 超幾何関数の離散鞍点法とその応用2019

    • Author(s)
      岩﨑 克則
    • Organizer
      微分方程式と逆問題をめぐって
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] 離散最急降下法とガウス連分数 Discrete steepest descent method and Gauss continued fraction2019

    • Author(s)
      岩﨑 克則
    • Organizer
      アクセサリーパラメータ研究会
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 超幾何連分数の漸近展開2018

    • Author(s)
      岩﨑 克則
    • Organizer
      第12回玉原特殊多様体研究集会
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] 超幾何級数の離散鞍点法とその応用2018

    • Author(s)
      岩﨑 克則
    • Organizer
      超幾何方程式研究会2018
    • Related Report
      2017 Research-status Report
  • [Presentation] Error estimates for hypergeometric continued fractions2018

    • Author(s)
      岩﨑 克則
    • Organizer
      アクセサリ・パラメータ研究会
    • Related Report
      2017 Research-status Report
  • [Presentation] 超幾何級数の漸近挙動と離散鞍点法2017

    • Author(s)
      岩﨑 克則
    • Organizer
      超幾何学校2017ポスターセッション
    • Related Report
      2017 Research-status Report
  • [Presentation] 代数曲面上の双有理写像の周期点とパンルヴェ方程式の周期解2017

    • Author(s)
      岩﨑 克則
    • Organizer
      第11回玉原特殊多様体研究集会
    • Related Report
      2017 Research-status Report
  • [Presentation] ガンマ和はガンマ積で書けない (岩崎克則(北大・理)との共同研究)2017

    • Author(s)
      蛭子彰仁(連携研究者)
    • Organizer
      超幾何方程式研究会 2017
    • Place of Presentation
      神戸大学瀧川記念学術交流会館 (兵庫県・神戸市)
    • Related Report
      2016 Research-status Report
  • [Presentation] 超幾何連分数について2016

    • Author(s)
      岩崎克則
    • Organizer
      第10回玉原特殊多様体研究集会
    • Place of Presentation
      東京大学玉原国際セミナーハウス (群馬県・沼田市)
    • Related Report
      2016 Research-status Report
    • Invited
  • [Presentation] 境界領域における超幾何関数のガンマ乗積表示について2016

    • Author(s)
      日下部美奈, 岩崎克則
    • Organizer
      2016年度函数方程式論サマーセミナー
    • Place of Presentation
      いこいの村能登半島 (石川県・羽咋市)
    • Related Report
      2016 Research-status Report
  • [Presentation] パンルヴェ方程式の幾何学2016

    • Author(s)
      岩崎克則
    • Organizer
      幾何学コロキウム
    • Place of Presentation
      北海道大学理学研究院 (北海道・札幌市)
    • Related Report
      2016 Research-status Report
    • Invited

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

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