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

Study od Coding-Theory

Research Project

Project/Area Number 09640043
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Algebra
Research InstitutionThe UniversitVVy of Tokushima

Principal Investigator

OHBUCHI Akira  University of Tokushima Associated Professor, 総合科学部, 助教授 (10211111)

Co-Investigator(Kenkyū-buntansha) TAKADA Ichiro  University of Tokushima Associated Professor, 総合科学部, 助教授 (20231392)
KASHIWAGI Yoshimi  Yamaguchi University Associated Professor, 経済学部, 助教授 (00152637)
Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
KeywordsCurve / Code Theory / Special Divisor / 代数曲線論 / 代数幾何学
Research Abstract

1. We classify smooth projective algebraic curves C of genus g such that the variety of special linear systems W^2_(C) has dimension g - 7. We prove that W^2_(C) has dimension g - 7 <greater than or equal> 0 if and only if C is either a trigonal curve, a double cover of a curve of genus two, a curve with very ample g^3_ or a curve with g^2_.
2. We classify smooth projective algebraic curves C of genus g with normally gen-erated line bundle of degree <greater than or equal> 2g - 3. And we prove that every very ample line bundle L of degree 2g + 1 - k <less than or equal> 2g - 5 with h^1(L) = h <greater than or equal> max(2, (k - 4)/3) is normally generated, if g <greater than or equal> 6k
3. Irreducibility of W^1_(C) for d <greater than or equal> g - (k - 2) [(h+3)/] - h + 1, where C is a curve of genus g which admits an odd prime degree k map onto a general curve C of genus h > 0 is proved. Also, the existence of a component of W^1_(X) with expected dimension on a general k-sheeted covering X over a curve C is shown.

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (18 results)

All Other

All Publications (18 results)

  • [Publications] E.Ballico C.Keem.G.Martens.A.Ohbuchi: "On curves of genus eight" Math.Z.227. 543-554 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Kato C.Keem A.Ohbuchi: "Variety of special linear systems on triple covering" Geo.Dedicata. 69. 53-65 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Ohbuchi: "On Difference of 4-goral linear systen on some curves" Serdica Math.(to appear).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Ohbuchi: "On some numerical relation of d-goral linear system" Tokushima J.31. 7-10 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Ohbuchi: "代数曲線上のnormal generationについて" 数理解析研究所講究録1065.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] E.Ballico, C.Keem, G.Martens, A.Ohbuchi: "On curves of genus eight" Math.Z. 227. 543-554 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Takao Kato, Changho Keem and Akira Ohbuchi: "Variety of special linear systems on triple coverings" Geom.Dedicata. 69. (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Ohbuchi: "On Difference of 4-gonal linear systems on some curves" to appear in Serdica Math.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Ohbuchi: "On Some Numerical Relations of d-gonal Linear Systems" Tokushima J.31. 7-10 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] E.Bollico,C.Keem,G.Martens,A.Ohbuchi: "On curves of genus 8" Math Z. 227. 543-554 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.kato,C.Keen,A.Ohbuchi: "Variety of special linean systems on triple" Ges.Dedicata. 69. 53-65 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] A.ohbuchi: "On Difference of 4-gonei linean systems onsome c" Serdica Math. (to appear.

    • Related Report
      1998 Annual Research Report
  • [Publications] A.Ohbuchi0: "On some numenial relation of d-gonel briean systa" Tokusima J. 31. 7-10 (1997)

    • Related Report
      1998 Annual Research Report
  • [Publications] A.Ohbuchi: "代数曲線上のnormal generationについて" 数理解析研究所講究録1065.

    • Related Report
      1998 Annual Research Report
  • [Publications] Takao Kato, Changho Keem Akita Ohbuchi: "On triple coverings of irrational curves" Tsukuba Journal. 21(2). 421-441 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Akira Ohbuchi: "On some numenical relations of d-gonal limean systems" Tokushima Journal. 31. 7-10 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Takao Kato, Changho Keem Akira Ohbuchi: "Vaniety of special linean systems on k-sheeted coverings" Geometriae Dedicata. (to appear).

    • Related Report
      1997 Annual Research Report
  • [Publications] Akira Ohbuchi: "On the difference of 4-gonal linean systems on some curves" Serdica Metal.J.(to appear).

    • Related Report
      1997 Annual Research Report

URL: 

Published: 1997-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi