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2010 Fiscal Year Final Research Report

The study of norm structure and various constants of Banach spaces, and its applications

Research Project

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Project/Area Number 20540158
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Basic analysis
Research InstitutionNiigata University

Principal Investigator

SAITO Kichi-Suke  Niigata University, 自然科学系, 教授 (30018949)

Co-Investigator(Kenkyū-buntansha) KATO Mikio  九州工業大学, 大学院・工学研究院, 教授 (50090551)
HATORI Osamu  新潟大学, 自然科学系, 教授 (70156363)
WATANABE Keiichi  新潟大学, 自然科学系, 准教授 (50210894)
Co-Investigator(Renkei-kenkyūsha) TAKAHASHI Yasuji  岡山県立大学, 情報理工学部, 教授 (30001853)
Project Period (FY) 2008 – 2010
Keywordsバナッハ空間 / James定数 / 三角不等式
Research Abstract

To study norm structure of Banach spaces, it is important of considering the form of unit sphere of the space. Many mathematical results are dependent on the sphere. To do this, we have several geometrical constants of Banach spaces, for example, von Neumann-Jordan constant, James constant and so on. In this research, we calculate the geometrical constant of absolute normalized space R^2. In particular, we calculate the James constant of extreme absolute normalized norms on R^2.
On the other hand, we continued to study the refinement of sharp triangle inequalities. At first, we show another proof of sharp triangle inequality and we have the equality conditions of the inequalities. Further, we succeeded a generalization of the operator version of Dunkl-Williams inequality and so on.

  • Research Products

    (22 results)

All 2011 2010 2009 2008 Other

All Journal Article (10 results) (of which Peer Reviewed: 10 results) Presentation (12 results)

  • [Journal Article] Schatten p-norm inequalies related to an extended operator parallelogram law2011

    • Author(s)
      Mohammad S. Moslehiam, Masaru Tominaga, Kichi-Suke Saito
    • Journal Title

      Linear Algebras and Applications Vol.455

      Pages: 823-829

    • Peer Reviewed
  • [Journal Article] Sharp mean triangle inequality2010

    • Author(s)
      Masatoshi Fujii, Mikio Kato, Kichi-Suke Saito, Takayuki Tamura
    • Journal Title

      Math. Inequal. Appl. Vol.13

      Pages: 743-752

    • Peer Reviewed
  • [Journal Article] Extremal structure of the set of absolute normalized norms on R^2 and the von Neumann-Jordan constant2010

    • Author(s)
      Naoto Komuro, Kichi-Suke Saito, Ken-ichi Mitani
    • Journal Title

      J.Math.Anal.Appl. Vol.370

      Pages: 101-106

    • Peer Reviewed
  • [Journal Article] Uniform non-1^n-ness of ψ-directsums of Banach spaces X+_ψY, J. Nonlinear Anal.2010

    • Author(s)
      Mikio Kato, Kichi-Suke Saito, Takayuki Tamura
    • Journal Title

      Convex Anal. Vol.11, No.1

      Pages: 13-33

    • Peer Reviewed
  • [Journal Article] The Dunkl-Williams type inequality for absolute value operators2010

    • Author(s)
      Kichi-Suke Saito, Masaru Tominaga
    • Journal Title

      Linear Alg. Appl. Vol.432

      Pages: 3258-3264

    • Peer Reviewed
  • [Journal Article] Sharp triangle inequalities for Banach spaces II2010

    • Author(s)
      Ken-Ichi Mitani, Kichi-Suke Saito
    • Journal Title

      J. Inequal. Appl. Vol.2010 Article ID 323609

      Pages: 17

    • Peer Reviewed
  • [Journal Article] The new geometrical constant of Banach spaces and its applications2009

    • Author(s)
      Ken-ichi Mitani, Kichi-Suke Saito
    • Journal Title

      Commentationes Mathematycznego Vol.49, No.1

      Pages: 3-13

    • Peer Reviewed
  • [Journal Article] Dual of two dimensional Lorentz sequence spaces2009

    • Author(s)
      Ken-ichi Mitani, Kichi-Suke Saito
    • Journal Title

      Nonlinear Analysis Vol.71

      Pages: 5238-5247

    • Peer Reviewed
  • [Journal Article] On the calculation of the James constant of Lorentz sequence spaces2008

    • Author(s)
      Ken-ichi Mitani, Kichi-Suke Saito, Tomonari Suzuki
    • Journal Title

      J.Math.Anal.Appl. Vol.343

      Pages: 310-314

    • Peer Reviewed
  • [Journal Article] Extremal structure of the set of absolute normalized norms on R^2 and the James constant

    • Author(s)
      Naoto Komuro, Kichi-Suke Saito, Ken-ichi Mitani
    • Journal Title

      Applied Math. Computation (掲載決定)

    • Peer Reviewed
  • [Presentation] On the James constant of absolute norms on R^22011

    • Author(s)
      小室直人, 斎藤吉助, 三谷健一
    • Organizer
      数理研研究集会
    • Place of Presentation
      京都大学数理解析研究所
    • Year and Date
      2011-02-14
  • [Presentation] absolute normの集合の端点構造について2010

    • Author(s)
      三谷健一, 斎藤吉助, 小室直人
    • Organizer
      数理研研究集会
    • Place of Presentation
      京都大学数理解析研究所
    • Year and Date
      2010-10-27
  • [Presentation] The sharp triangle inequalities and its applications to the geometry of Banach spaces2010

    • Author(s)
      斎藤吉助
    • Organizer
      CIA10
    • Place of Presentation
      Hungary
    • Year and Date
      2010-09-23
  • [Presentation] Absolute normの単調性とその応用2010

    • Author(s)
      斎藤吉助, 三谷健一, 小室直人
    • Organizer
      数理研研究集会
    • Place of Presentation
      京都大学数理解析研究所
    • Year and Date
      2010-08-31
  • [Presentation] Refinements of sharp triangle inequalities in Banach spaces and its applications2009

    • Author(s)
      斎藤吉助
    • Organizer
      Abstract Harmonic Analysis 2009
    • Place of Presentation
      National Sun Yat-sen University Kaohsiung, Taiwan
    • Year and Date
      20091218-20091222
  • [Presentation] On sharp triangle inequalities in Banach spaces and its applications2009

    • Author(s)
      斎藤吉助
    • Organizer
      Banach and Function Spaces 2009
    • Place of Presentation
      Kyushu Institute of Technology, Tobata Campus Kitakyushu, Japan
    • Year and Date
      20090914-20090917
  • [Presentation] Dual of two dimensional Lorentz spaces ant the James constant2009

    • Author(s)
      斎藤吉助
    • Organizer
      Analysis Inequality and Homogenety theory
    • Place of Presentation
      Lulea, Sweden
    • Year and Date
      20090608-20090611
  • [Presentation] Extremal structure of absolute normalized norms on R^2 II2009

    • Author(s)
      小室直人, 斎藤吉助, 三谷健一
    • Organizer
      The Sixth International Conference on Nonlinear Analysis and Convex Analysis
    • Place of Presentation
      Tokyo Institute of Technology
    • Year and Date
      20090327-20090331
  • [Presentation] Dunkl-Williams不等式と作用素不等式について2009

    • Author(s)
      斎藤吉助
    • Organizer
      作用素論・作用素環論研究集会
    • Place of Presentation
      奈良教育大学
    • Year and Date
      2009-11-19
  • [Presentation] Sharp triangle inequalityの等号条件について2009

    • Author(s)
      三谷健一, 斎藤吉助
    • Organizer
      数理研研究集会
    • Place of Presentation
      京都大学数理解析研究所
    • Year and Date
      2009-05-21
  • [Presentation] Extremal structure of absolute normalized normes on R22008

    • Author(s)
      小室直人, 斎藤吉助, 三谷健一
    • Organizer
      Asian Conference on Nonlinear Analysis and Optimization
    • Place of Presentation
      Japan
    • Year and Date
      2008-09-15
  • [Presentation] Refinements of triangle inequalities in Banach spaces2008

    • Author(s)
      斎藤吉助
    • Organizer
      International Workshop on Interpolation Theory Function Spaces and Related Topics
    • Place of Presentation
      Toledo, Spain
    • Year and Date
      2008-09-08

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Published: 2012-01-26   Modified: 2016-04-21  

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