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UNBOUNDED REPRESENTATIONS OF QUANTUM ALGEBRAS AND THEIR ATTACHED

Research Project

Project/Area Number 17540165
Research Category

Grant-in-Aid for Scientific Research (C)

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

Principal Investigator

OTA Schoichi  Kyushu University, Faculty of Design, Professor (70107176)

Co-Investigator(Kenkyū-buntansha) INOUE Atushu  Fukuoka University, Faculty of Science, Professor (50078557)
Project Period (FY) 2005 – 2007
Project Status Completed (Fiscal Year 2007)
Budget Amount *help
¥1,650,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥150,000)
Fiscal Year 2007: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
KeywordsUNBOUNDED OPERATOR / q-DEFORMED OPERATOR / q-NORMAL OPERATOR / q-HARMONIC OSCILLATOR / CIRCULAR OPERATOR / q-生成作用素 / 調和振動子 / q-正定値 / q-変形調和振動子 / q-変形生成作用素 / q-formally正規作用素 / 生成作用素
Research Abstract

The research is devoted to analyzing operator representations related to some q-deformed quantum harmonic oscillator and also to studying well-behaved unbounded representations of *-algebras. V. Bargmann showed in 1961 that the creation operator in the quantum harmonic oscillator is unitarily equivalent to the operator of multiplication by the independent variable on Segal-Bargmann space. Therefore, the creation operator is extended to a normal operator on a possibly larger Hilbert space. Recently, many variants of deformed oscillators with deformation parameter q occur in quantum groups theory. One possible variety is based on the relation xx*-qx*x=1, where q is positive real number and is not equal to 1. Motivated by the result of Bargmann, we naturally present a question whether a so-called q-creation operator x* is extended to some operator which is near to a kind of normal operator in a sense. We introduce a notion of 'q-positive definiteness' for a densely defined operator on Hilbert space and it is observed that the creation operator x* satisfies such a condition. We proved that, if a densely defined operator has invariant domain and satisfies 'q-positive definiteness' , then it is extended to a q-formally normal operator on a possibly larger space. Especially, the Bram-Halmos theorem for bounded subnormal operators is obtained by taking q=1 in the above. Moreover, it implies that the q-creation operator mentioned above is extended to a q-formally normal operator.

Report

(4 results)
  • 2007 Annual Research Report   Final Research Report Summary
  • 2006 Annual Research Report
  • 2005 Annual Research Report
  • Research Products

    (14 results)

All 2007 2006 2005

All Journal Article (8 results) (of which Peer Reviewed: 4 results) Presentation (6 results)

  • [Journal Article] q-positive definiteness and related operators2007

    • Author(s)
      S.Ota, et. al.
    • Journal Title

      Journal of Mathematical Analysis and Applications 329

      Pages: 987-997

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Final Research Report Summary
    • Peer Reviewed
  • [Journal Article] Unbounded *-representations of tensor product locally conve x^*-algebras induced by unbounded C^*-seminorms2007

    • Author(s)
      A.Inoue, et. al.
    • Journal Title

      Studia Mathematica 183

      Pages: 259-271

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Final Research Report Summary
    • Peer Reviewed
  • [Journal Article] q-positive definiteness and related operators2007

    • Author(s)
      S., Ota, F H., Szafraniec
    • Journal Title

      Journal of Mathematical Analysis and Applications Vol. 329

      Pages: 987-997

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Journal Article] Unbounded *-representations of tensor product locally convex *-algebras induced by unbounded C*-seminorms2007

    • Author(s)
      M., Fragoulopoulou, A., Inoue
    • Journal Title

      Studia Mathematica Vol. 183

      Pages: 259-271

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Journal Article] q-positive definiteness and related operators2007

    • Author(s)
      Schoichi Ota, et. al.
    • Journal Title

      Journal of Mathematical Analysis and Applications 329

      Pages: 987-997

    • Related Report
      2007 Annual Research Report
    • Peer Reviewed
  • [Journal Article] q-deformed circular operators2006

    • Author(s)
      S.Ota
    • Journal Title

      Integral Equations and Operator Theory 54

      Pages: 555-569

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Final Research Report Summary
    • Peer Reviewed
  • [Journal Article] q-deformed circular operators2006

    • Author(s)
      S., Ota
    • Journal Title

      Integral Equations and Operator Theory Vol. 54

      Pages: 555-569

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Journal Article] q-deformed circular operators2006

    • Author(s)
      太田 昇一
    • Journal Title

      Integral Equations and Operator Theory 54

      Pages: 555-569

    • Related Report
      2006 Annual Research Report
  • [Presentation] q-positive definiteness and related operators2007

    • Author(s)
      太田 昇一
    • Organizer
      日本数学会秋季総合分科会
    • Place of Presentation
      東北大学
    • Year and Date
      2007-09-22
    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Annual Research Report 2007 Final Research Report Summary
  • [Presentation] q-positive definiteness and related operators2007

    • Author(s)
      S., Ota
    • Organizer
      Mathematical Society of Japan meetings
    • Place of Presentation
      Tohoku University
    • Year and Date
      2007-09-22
    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Presentation] 作用素のq-正定値性とq-正規拡大について2006

    • Author(s)
      太田 昇一
    • Organizer
      数理解析研究所研究集会
    • Place of Presentation
      京都大学
    • Year and Date
      2006-10-11
    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Presentation] On q-posotive definiteness of an operator and a q-normal extension2006

    • Author(s)
      S., Ota
    • Organizer
      R.I.M.S.Conference'Recent Developments in Theory of Operators and Its Applications'
    • Place of Presentation
      Kyoto University
    • Year and Date
      2006-10-11
    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Presentation] q-deformed circular operators2005

    • Author(s)
      太田 昇一
    • Organizer
      日本数学会秋季総合分科会
    • Place of Presentation
      岡山大学
    • Year and Date
      2005-09-21
    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2007 Final Research Report Summary
  • [Presentation] q-deformed circular operators2005

    • Author(s)
      S., Ota
    • Organizer
      Mathematical Society of Japan meetings
    • Place of Presentation
      Okayama University
    • Year and Date
      2005-09-21
    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2007 Final Research Report Summary

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Published: 2005-04-01   Modified: 2016-04-21  

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